Let’s Interview: Longtime ROM Hacker NesDraug!

Let's Interview:


ROM Hacker

Interview conducted by


Let’s Interview: Longtime ROM Hacker NesDraug!

With projects such as The Legend of Mario, Beatles Adventures in Pepperland and Panic At The Mario Disco, NesDraug has quite the history in the ROM hacking community. He’s modified numerous games in the Mario and Zelda series, added extra functionality to a fair few games, and finished up games by all manner of other greats too, like Mario’s Keep.

It’s quite the resume, and one that’s made us wonder how it’s all possible.

So in this article, we’re going to find out! To see what goes into all these projects, how they’re made, and what inspires Nes Draug to do the work he does.

Let’s go!

The Interview

Starting with the usual intro. So who are you? Who is NesDraug?

NesDraug is the moniker I use for my romhacking projects. I’m also Thomas, a 36 year old jack-of-all-trades media producer from Sweden. Over the years I’ve had some cool video game ideas stuck in my head. Like “What if Mario 2 was a Beatles game” or “What if The Legend of Zelda was a Mario-game?” To me that sounds like fun games that I would love to play! I simply needed them to exist in the universe.

Where did your name come from?

I mainly hack NES games. The Nintendo Entertainment System was my childhood console that I grew up with. A draug is basically the scandinavian version of a zombie and it reflects the state I’m in after sinking too deep into these projects.

And what was your first game?

Super Mario Bros. It came with the console.

What games are you playing at the moment?

I’m really into randomizers of NES games and hopefully my latest hack will be randomizable pretty soon. That way I can experience it for the first time! But I play more modern games too. Mainly co-op. Broforce is awesome. Also I love Deep Rock Galactic. Got 500+ hours in that game.

Deep Rock Galactic Artwork

NESDraug has been playing a lot of this game recently

Onto game dev now. How did you get into game development?

Game development has always been a hobby of mine. I used to make Monopoly clones on cardboard when I was a child and I’ve just continued to explore that corner of my creativity. I’m also a playwright and a media producer but I just felt that I had to explore game development a bit more seriously. During the pandemic I actually took a year off to study IndieGameDev. Now I do music for games and hold lectures in game dev for youngsters at the local College.

How about ROM hacking? How did you get started there?

In 2018 I was suffering from post production blues after producing my first (and so far only) musical. I dived into romhacking as pure escapism and/or therapy. That gave me my creativity back.

Have any other creators inspired you here?

Oh, sure a lot of great rom hackers that came before me. I’m just standing on the shoulders of giants. I have a really hard time with numbers and coding is not my forte so I often rely on tools and patches created by the romhacking community. I always try to give proper credit when possible. One of my first proper hacks (Mario’s Keep) was actually abandoned by the legendary hacker w7n, I picked it up and finished it, learned a lot in the process. That’s probably why that game is fun but a bit… shall we say “uneven”?

Mario's Keep Title Screen

NESDraug finished up w7n’s hack Mario’s Keep

Were there any hacks you didn’t end up releasing?

Yeah. I have a pretty big backlog of unreleased and unfinished hacks. They are usually just about 10% finished and not enjoyable to play. “Dynamite Mario” is one, that was a project I scrapped – I later finished it as “Bob-Omb Mario” which is obviously a better idea. “Super Mario Cage Fight” is another SMB1 hack that I’ll never finish. I love Bionic Commando so I always wanted to make a “Bionic Commando 2” or something like that. “Super Jumpman World” is a SNES hack in which I wanted to make easier levels for an existing hack called “Jumpman Returns” by Big Brawler. Often hackers make the games too hard, I’m not into kaizo stuff. “The Legend Of Luigi” was the first version of my latest hack. Yeah, that one is like a really clunky prototype, might actually be fun to try it out just to compare it to the finished version. Oh, somewhere I got an “Unnamed Lode Runner Hack” that I lost interest in.

How do you decide which games to mod anyway? You’ve certainly modded a lot of different titles so far…

Have you ever had a dream that you, um, you had, your, you- you could, you’ll do, you- you wants, you, you could do so, you- you’ll do, you could- you, you want, you wanted to do you so much you could do anything?

What’s your ASM experience like? Seems like quite a few of these hacks have a fair few new features and mechanics…

Oh, I’m an assembly language illiterate. I do a lot of hex editing and trial and error. Sometimes I do poke around in the disassembled code, with various results. I’ve tried to understand 6502 and asm6 and whatnot but nothing sticks. I just get bored and confused. Like a fellow romhacker once said: “You’ve been doing this for years and you’re still asking for help to do pretty basic stuff, that’s kinda weak”. I’m not at all ashamed of that. It’s an inconvenience, true. But it seems like I’m not built to be a coder or a programmer. It’s like if a Triathlete would be sad that he sucks at baseball. I can do just about every aspect of gamedev: music, graphics, level design, worldbuilding, utilise interesting game mechanics, even the artwork… but not coding, so what I do is ask for help and get other people to show me how, or just do it for me.

One thing you seem to make a lot of are co-op hacks. What made you want to add multiplayer to all these titles?

CorpseGrinder and Ti turned the original Super Mario Bros. into a simultaneous two player experience. I was just blown away by that. I had longed for that for decades. Back in the day you had to take turns and that annoyed the shit out of my impatient seven year old little brain that I had to watch my little sister play. I got to experience it way later with New Super Mario Bros. Wii, sure. But how cool is it to change the original game! That’s so rad. I took their hack and added some new levels and ideas and then I just kept looking for co-op games. I’ve curated a list of co-op hacks on RHDN here.

Super Mario Bros Co-op

The original co-op hack that kicked off a whole genre

And what’s it like implementing that? Seems like a ton of work to add such functionality…

Yeah, I didn’t have the source code and could not get it from the hack developers so there was a lot of hex editing, guessing, comparing lines of code with the original game and naturally: asking for help. There’s a couple of romhacking forums and discords to ask for advice. Usually people will help out if you have an inspired idea. Basically I did the hack first in SMBUtility, YY-CHR and Famitracker and then ported the changes from a clean SMB1 rom into the two player hack. It was tedious but also stimulating.

Either way, Mario hacks seem to be another speciality, with many of your projects being mods of the NES Mario titles. Are you a huge fan of that series?

Well, mainly the first 8-bit Mario games. That’s what I grew up with so it has a special place in my heart. Mario is just a strong and recognizable character, so it’s fun to put him in unexpected places and situations.

What’s your favourite Mario game on NES?

Super Mario Bros. 3. Now, imagine if that had simultaneous 2-player? There’s this guy working on a hack like that but sadly I think they got other priorities. Can’t blame them. It’s a pretty niche request. I’ve thought about making a SMB3 hack but I actually like the challenge with the limitations of the original SMB. There’s just too many possibilities with SMB3, it’s a huge game.

Super Mario Bros 3 Mix Title

Hacks like Super Mario Bros 3 Mix have shown the potential of the Mario 3 engine

One of your most interesting projects is The Beatles Adventures in Pepperland, a mod of SMB 2 based on the Yellow Submarine movie starring the Beatles. What made you decide to create a mod based on that?

YouTube player

Oh, I think I first had that idea back in 2006. But I couldn’t find any tools for hacking Super Mario Bros. 2 and I think I was pretty busy with failing at becoming a rock star at that point of my life so the idea was tucked away in the back of my head until 2018 when I started to investigate how to make it happen. I found my co-developer Shauing at a forum and he did the music and a lot of the heavy lifting with the coding. I was the main developer and creative leader but a lot of people really loved the idea and helped out. There’s a special thanks section in the artwork I made for that hack.

How did you decide what characters to respite enemies and items as?

Some things just feel self-explanatory. I mean. Naturally Ringo is Toad. Why? He’s a bit shorter? He’s the funny one? I don’t know. It just seemed like such a good fit. George is not the leader of the group but he’s all round like Mario, and dressed in red on the Sgt. Peppers cover so, that looks good. I’m pretty intuitive with these things. Tryclyde should be the The Four-Headed Bulldog from the Yellow Submarine, it’s just a match made in heaven. The whole idea just felt like a dream. Of course the 1968 film Yellow Submarine would translate perfectly into the subcon world of Super Mario Bros. 2. In my mind it just does! It’s all in the mind, y’know?

What was it like converting the band’s music to a format that worked for a NES game like this? Were any songs particularly tricky to work with?

People have poked in these games for decades so there are some documentation on how to do stuff if you’ve got the patience for it. I tried and only managed to get a horrible version of Hey Bulldog… thankfully Shauing joined the team. Me and Shauing decided together what songs to include. We took songs from the Yellow Submarine soundtrack and he tailored them into these fantastic 8-bit renditions. I think I pushed him a bit hard at times but he was just as dedicated to this project as me, so we pulled through with a killer soundtrack. I’d do rough mockups on a synth with kinda 8-bit sounds as suggestions on how to arrange the songs and he would (painstakingly) edit the hex code and just brute force it. We had the disassembled code at our disposal but he just did it in hex in the emulator anyway because that was the way he learned how the sound engine worked.

Heck, were any scrapped altogether due to tech limitations or not working well?

Well, the whole soundtrack of Yellow Submarine could not fit. We considered having a new track for every single level but that would have been too labour intensive and also take up too much space. I think me and Shauing only had one dispute and that was for the end credits. We agreed on ending the game with “All You Need is Love” and Shauing made the entire song in 8-bit. The whole song! I really wanted the hack to mimic the way the original game goes into “lullaby mode” when Mario wakes up in the end credits, just to tap into that nostalgic feeling even more. Shauing wanted to make an as faithful 8-bit version of the song as possible, so what we ended up with is some kind of compromise. I think it works great, I still get some goosebumps.

If you were going to redo it again, what changes would you make?

Redo the Beatles hack? I already did! After a week or so after the original release I realised that I accidentally left some levels inside the hack that was made by RidleyX and GlitchCat7. That was really embarrassing. It is always my intention to give people proper credit. The way it happened was that before I started working on The Beatles Adventures in Pepperland I gathered all the best SMB2 hacks I could find and put ‘em all into SMB2Edit, just to learn – to see what made these levels great! Well, sometime along the way (we worked on this hack for over 2 years) I totally forgot about that. I thought I had made all the levels by myself but there were still like 2 levels left in the game by RidleyX and GlitchCat7. So Shauing and I redid them and uploaded version 1.2. I’m so relieved there’s never any money or profit whatsoever involved in these projects. The legal ramifications would just be hell to deal with. There’s just pure inspiration, creativity and shared interests among retro enthusiasts and we’re just trying to learn and have some fun.

Onto the Legend of Mario now. Why did you decide to make Zelda 1 into a Mario game?

The Legend of Super Mario Title Screen

The title screen for The Legend of Super Mario, a Mario themed Zelda 1 hack

It just seemed like a good idea. I was surprised that no one had done it already. There was a sprite hack but nothing as complex as I had in mind. I make the games I want to play or that I would have loved as a kid.

And how did you decide what enemies, characters, etc to convert into what Mario equivalents? Zelda 1 and Super Mario Bros certainly have very different mechanics for their enemies and bosses…

From the get go people in various forums and discord servers liked the idea and came with ideas. I made a list of what enemies seemed to fit based on my own and other people’s ideas. Since SMB3 is my favourite game and the entire overworld is based on the SMB3 worlds most of the graphics are pulled from or reworked versions of SMB3 graphics. Yeah, Zelda is a top down game and Mario is a platformer so I had to tweak some enemies quite a bit.

What was the thought behind the overworld and dungeon design? It’s certainly been changed a bit from the original game…

The overworld is actually the worlds from SMB3. It’s a totally crazy idea and I made a mockup map where I puzzled them together. Let me show you. Gosh darnit, I can be so stubborn with these things sometimes. It’s a crazy idea to try to transform SMB3 into TLoZ but I did it… with some creative liberties.


Super MarioBros 3 Map Concept

NesDraug’s original concept for a Zelda 1 map based on the worlds from Mario 3


Legend of Super Mario Overworld Map

The final overworld map for the Legend of Super Mario

I started this hack 3 years ago and I was so close to giving up on it, but then someone called P-Tux7 told me about MetalMachine and that he is developing a very competent Zelda Maker so I joined his discord and got early access to the Zelda Reloaded Maker. Without that tool I would not have been able to finish the hack. Well, I might have released it as that unfinished Legend of Luigi prototype.

The mixed music is a neat touch, and definitely keeps the feel of both franchises intact here. How did you decide what songs to combine?

YouTube player

It’s the two main themes from Super Mario and Zelda combined. I love mashups and have listened to mashups ever since DangerMouse put out the Grey Album (JayZ’s Black Album + The Beatles’ White Album). All those years of listening to mashups have given me an ear for how to transform music from one style to another.

One thing that seems minimal here are completely custom enemies and mechanics. Did you ever think of coding some of your own stuff there to give things even more of a Mario feel?

Nah. The main idea is that this is indeed The Legend of Zelda with a Mario touch. Sure, one might go into the code and make arrows behave like fireballs and change the sword into a fist or being able to jump or sprint, but there’s also something charming with working with what you got and keeping it close to the original gameplay. It’s not perfect and that’s fun. It’s probably a bit broken but that’s what makes it interesting. “There is a crack in everything – that’s how the light gets in.”

Anything you’d do differently if you remade the game?

Eh… yeah. Funny you should ask. I had like 9 beta testers but now that I’ve seen other people stream the game I’ve got more feedback and found some minor bugs. A revised version is very much a possibility, and I might add a second quest. Oh, also MetalMachine is looking into the possibility of randomising my hack so that might be a thing in the not so distant future.

Either way, the game has done really well upon release, with some news sites even writing articles about it. How does it feel to see your work get this amount of attention?

I like that the game gets attention and that people seem to enjoy it. I made it for my own amusement and because I wanted it to exist in the universe. I’ve lurked in some streams, taking notes. Shoutout to Mike Matei, who said he’d buy me a beer! Although I don’t think I’m leaving Sweden anytime soon since I don’t fly. Something, something climate. Something, something environment. Also I hate travelling to begin with. I love beer though.

Which of your projects is your favourite and why?

I’m so glad that The Beatles Adventure in Pepperland got made. I had that dream for so long. Having great ideas is like being pregnant, you just want to get them out in the world and then keep them safe and healthy.

Any you feel didn’t live up to their potential?

Mario’s Keep is quite a mess, but it was one of my first hacks and there’s some fun stuff there. I also made a co-op version of that one. A lot of my co-op hacks fly under the radar it seems. Perhaps investing the time in finding a buddy to play with in couch co-op or going through the hassle of online emulation is just too inconvenient. I’m glad speedrunner extraordinaire Kosmic played the hacks tho!

YouTube player

What games do you want to hack in future?

You know what? After exploring the possibilities of romhacking over the last five years or so I think I’m retiring from the rom hacking scene. There’s still stuff I want to do and I have lots of ideas but it’s a hobby that turns into an obsession at times. I’m happy with the people I’ve worked with and the things I’ve learned but now I wish to develop a fun (and profitable) game of my own! Creating my own intellectual properties or doing some freelance work in the retrogaming business. Anyone hiring?

And what projects by other hackers look super promising to you?

Kirbymimi is working on a SMB3 two player hack, I’d love to see that. ScarletVixen has been working on Mario Adventure 3: Mushroom Mayhem for years and I really want to play it because it looks awesome! Also W7N has been working on this “Mario Gaiden Project” and that turned into “Celeste Mario’s Zap & Dash!” so a lot of cool hacks can be made with that new engine.

Celeste Mario's Zap And Dash

The title screen for Celeste Mario, an insanely well put together mod of the original game

Finally, what advice would you give someone wanting to get started with making ROM hacks?

Don’t be afraid to ask for help and advice. If you have a dream and wish to make it come true you should look for like-minded people for ideas and encouragement and ask more knowledgeable people for hints and where to find more info. Some ideas are just too beautiful to remain ideas.

Thanks for the advice NesDraug! Yeah, you should definitely ask for help if you need it, especially in a community orientated field like ROM hacking or modding. No one can master everything after all.

Either way, thanks for your hard work making all these different hacks over the years, and we wish you all the best in your indie game career too! Based on the level design work shown in your projects and your experience with so many aspects of game design, you definitely have the skills to make some insane video games of your own in future, and it’ll be exciting to see how those ideas evolve and continue when implemented in an engine without technical limits and with the power of modern day technology.

So thanks for the interview, and we’ll be happy to check out any future games you make too, whether they be ROM hacks, indie games or anything else.

Still, what did you folks reading this think of the interview? Did you enjoy reading about NesDraug’s projects and development process? Are there any questions you think we missed out on here?

Leave your thoughts in the comments below, on social media, or on our Discord server today!

NesDraug on Social Media