Let’s Interview: Mushroom Kingdom Fusion Lead Developer Dooki51!

Let's Interview:


Game Developer

Interview conducted by


Let’s Interview: Mushroom Kingdom Fusion Lead Developer Dooki51!

As anyone who knows about the Mario fangaming scene knows, Mushroom Kingdom Fusion is one of (if not the) most ambitious fan game of all time. Started in 2008 by a developer called JudgeSpear, the game has numerous characters from all over the world of gaming team up in an attempt to stop a monster called Legion from taking over the multiverse. It’s the kind of game that has Mario and Sonic fighting through Hyrule, Link fighting through a Metal Slug series army base or or Simon Belmont exploring Zebes.

It’s ambitious, it’s awesome, and it’s basically Super Smash Bros if it was a 2D platformer instead of a fighting game.

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And we’ve interviewed just about everyone who’s ever worked on the game. We’ve interviewed JudgeSpear, who started the project back in 2008. We’ve interviewed Feguelion, the guy who took it over from JudgeSpear after the latter quit to work on Super Mario Fusion and various indie projects.

Then yesterday we interviewed D-TurboKiller, who was the lead through 2008. This left just one notable figure, the current lead developer Dooki51.

So it’s time we interviewed him, and wrapped up our Mushroom Kingdom Fusion developer interview series for good. You ready? Let’s do this!

Well, you know the drill here, let’s have a bit of personal background to start things off. Who are you Dooki51?

Good question. To be honest, I’m still trying to figure that out myself! However, I can tell you what I do. I’m the current lead developer for Mushroom Kingdom Fusion and am looking to get further into programming as well. I also create things for the SiIvaGunner YouTube channel.

Dooki51's Avatar

Dooki51’s avatar on social media sites

Where did your username come from anyway?

Beats me. I made my username back when I was very young. I can’t really change it now because I’ve already made a lot of things (as well as a lot of friends) under this username. I don’t really remember the significance of it either.

How about your interest in gaming? What was your first game?

My interest in gaming started when my family got a computer with internet access. I grew up on a lot of flash games and fan-made games as a whole. I can’t for the life of me remember what the first flash game I ever played was. The first console we got was a Wii and the first game I played on there was Mario Party 8. I’m a huge fan of point and click adventure games, but I’m also a fan of Mario games. Speaking of which…

Mario Party 8 Scene

Mario Party 8 was Dooki’s first ever console game

What about the Mario series in particular?

Mario flash games were always my favorite when I was growing up, even if some of them weren’t all that good. Mario games were always my favorites even though I had very few of them. I think the biggest revelation I had when it comes to gaming when I was younger was finding out about emulators and being able to play Super Mario 64 right on my computer! I have fond memories of just playing Mario 64 for quite a while when I was younger and I still find it fun to play to this day. The most recent Mario game I’ve played through is Super Mario Odyssey, and that one’s really fun as well.

Super Mario Odyssey

Super Mario Odyssey is Dooki’s most recently played Mario game

Are you playing any interesting games at the moment?

I’m replaying Bioshock 2 at the moment. It’s quite a fun game to go through. Other than that, I’m also trying to go through some of the metroidvania style Castlevania games.

Either way, let’s talk game dev now. How did you get into game development?

As odd as it sounds, my game development history started exactly when I started working on MKF. Personally I wouldn’t recommend anyone do what I did because I essentially dived into the deep end of developing a game. Other than that I was mostly just modding a few existing games that have their resources easily accessible. That being said, I think the closest I’ve ever gotten to working on a gaming project is looking into how Source and Goldsrc games handle some sound systems and messing around with the scripts.

What about fan games? How did you find the Mario fan game scene?

Starting with flash games like Super Mario Flash, Super Mario Sunshine 64, Super Mario 63, and others, I eventually stumbled upon Mario Fan Games Galaxy (MFGG) and found a plethora of Mario fangames that are just amazing. I found MKF through MFGG, funnily enough. Of course, of all the games I grew up with, MKF stood out the most because of how many games are referenced in it and the crazy fun gameplay it has.

Did you work on any interesting projects before Mushroom Kingdom Fusion?

Game projects? Nope. I’ve made things for SiIvaGunner if that counts.

Are there any other fan games you really like? Perhaps even ones that inspired some of your work on MKF?

A lot of the flash games I grew up with inspired me to work on MKF, along with a lot of things that come from MFGG in general. A few examples are Super Mario Bros Crossover, Super Mario Bros X, and Super Mario Stardust. Also, the Normal Super Mario Bros series, while comedic in nature, also references a ton of other games and is definitely an inspiration of mine.

Super Mario Stardust

Super Mario Stardust was an inspirational game here

And what made you decide to take the lead on MKF anyway? Why did you become the lead for this project?

Back in 2018 when D-TurboKiller started to work on MKF again it gave me hope that the project would be completed once and for all. Around Christmas of the same year, he announced that he would stop working on the game himself for a variety of reasons. At that point I decided to look into the game’s source to see exactly what there was to work with and looked into how I could cross off a lot of things from D-Turbo’s todo list for the game. Ever since then I became the lead for the project. It wasn’t really anything I just decided to do, but rather it just turned out that way because I was the only one working on it to such an extent. As for why I’m still developing the game though? I grew up with MKF and seeing it be completed would be like paying back all of the fun times I had with it. I’ve been working on it since January of 2019.

Do you think your predecessors did a good job with the game before you took over?

Yes and no. One thing I need to clear up is that while JudgeSpear was the original creator of MKF (back when it was known as Super Mario Fusion: Mushroom Kingdom Hearts), it was Obreck who was the real backbone of the game and added almost all of the biggest features starting from around v0.2. He was the one who added the character swapping system as well as almost every character’s unique abilities (even Mario’s spin jump!).

Now to answer the question more specifically, I think they were definitely ambitious and added a lot of fun things to just mess around with. They did a great job with creating a basic engine over the original version of Hello Engine 3, but so many areas left a lot to be desired. Hello Engine 3 suffered from a lot of inadequately optimized systems due to being very poorly programmed at this point in the engine’s history. The additions made by the Fusion team were programmed better but still lacked proper documentation. The lack of proper documentation meant that most of the other devs at the time were afraid of breaking the game by changing the fundamental systems.

What would you have done differently had you been the game’s original creator?

I would probably have tried to finish the basic engine (including every single character) and figuring out what the basic elements for every type of game object would be. MKF tried to add a lot of new features in the middle of development, some of which were able to stay (e.g. red coin system) and others that had to be cut because the game was too far in development to change them (e.g. the Snake codec system replacing message blocks).

Has MKF’s development taught you any interesting game design/development lessons? If so, what are they?

Start small. Only add new things when everything that’s already in your project works as it should. I can’t stress enough how important it is to make sure everything works before adding new things. Also, the KISS principle (Keep It Simple, Stupid) applies when working on just about anything, but it especially applies with games. One last thing I’d like to go over is knowing when to cut certain features when they just aren’t working out. If a feature just isn’t working out properly even after asking for help with it, then it’s usually better just to cut it out. The same can also be said when a feature actively hinders development. It was a tough call to remove Collision Chaos from MKF because it was effectively finished. The main reason it was cut is because its features were being problematic and were getting in the way. It was an overdeveloped stage that was ultimately not worth keeping. It might be revitalized in a different form, but there are no guarantees.

Collision Chaos

Collision Chaos was cut for being overly complex

Let’s talk content now, starting with the characters. What’s your favourite character to play as in MKF?

My favorite character in MKF was and still is Wario. He’s just a ton of fun to use because he plays in a style that’s very similar to the first Wario Land game. Not to mention, his power-ups are quite unlike any other character’s.

Awazon Caverns

Wario is Dooki’s favourite character to play as

Any you don’t really care for?

The characters that I cut from the game were generally the ones I didn’t really care for. But even aside from my personal opinions, it was inevitable that they had to be cut. MKF was too far in development to feasibly flesh out Kirby. Meta Knight was severely unfinished and was effectively duct-taped into the game by 0.53. Ryu Hayabusa had the most development out of all the cut characters, but he was still buggy and had quite a ton of balance issues. His wall-climbing ability effectively broke the level design. Samus had no work done for her aside from a few sprite sheets that were recovered fairly recently, but there was absolutely no coding work done for her.

Samus Spritesheet

A spritesheet for Samus that was going to be used for her appearance in MKF

How about favourite levels and boss fights? Any you want to list there?

Here’s several of my favorites from the game: Birabuto Bash, Scandinavian Campaign, Skullman’s Wasteland, Forest of Silence, Ruined City, Fiddler’s Green, Mystic Forest, Toyland, Superflat Zone, Awazon Caverns, Covenant Assault, Diamondus, and Neon Labyrinth. The world boss level of world 2, Bridge to Morden, is also quite great.

Birabuto Bash

Birabuto Bash (A Super Mario Land world 1 remake) is a favourite

Forest of Silence

The spooky Forest of Silence is one of Dooki’s favourite levels

Neon Labyrinth

Neon Labyrinth is another favourite

And on the flip side, what levels and bosses don’t you like and why?

My least favorite levels are the ones that are either too long or use autoscroll. I don’t like the former because it feels like those stages overstay their welcome, while latter stages tend to feel longer than they actually are.

There have been some insane new stages showcased recently, with Castle Dracula and the Forest Temple being two of the highlights there. Which of these newer stages do you like the most and why?

I think all of the newer stages are great, and it’s especially great now that some of the older stages are being revamped to feel less like 1 to 1 remakes of levels from previous Mario games.

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Are there any interesting levels and bosses in development that you think will be amazing when done?

Yes, but I won’t spoil many specifics about them. The final level of world 5 is definitely gonna be a highlight since it’s receiving a complete redesign from its original unfinished state. The world 0 levels are also being developed finally, but those are classified and I won’t give out any information about them. It’ll be the only world whose levels will not be publicly revealed.

What about characters? We do hear a few new playable characters are in the works right now…

I don’t really want to reveal anything about new characters because I honestly don’t know if we’ll develop them, but there are only two characters that could potentially be developed. Whether or not we’ll actually be able to create them depends on A) if we can find good, unique gameplay ideas for them and B) if we have all of the assets necessary to complete them (sprites, sounds, code, etc.). I can say one thing though: neither of the two are Kirby or Meta Knight. Unfortunately for all the Kirby fans out there, the pink puffball is just too complicated to work into MKF this late into development. Having Meta Knight alone would also be unusual so unfortunately he’ll have to stay cut as well.

Either way, it seems development plans have changed a bit since you took over. What are the biggest changes you’ve made as lead developer overall?

There’s a lot to be said here, but I’ll answer in bullet-point format to keep things simple:

  • In general the physics have been improved and many major bugs have been fixed
  • Still ongoing but I’m rebalancing all of the characters so that they all have a reason to be used over other ones
  • Kirby, Samus, Ryu, and Meta Knight have all been cut.
  • Collision Chaos, Eye of the Storm, and Arcade Factory have been cut
  • The game has more or less been disconnected from its original story

And what’s going on with the game’s story right now anyway? Last we heard there were multiple villain groups and alliances, a two part world 0 and a whole bunch of OCs. What’s the story like now?

Simply put, there won’t really be one. If you want a longer answer, the game’s original story was its biggest problem because of how overcomplicated and demanding it was. Just because a lot of what was written sounded cool on paper doesn’t mean it would actually be fun to develop. However, just because we’re abandoning the old story doesn’t mean the game won’t have a story at all. It’s just that the story will be pushed to the side and will be a lot more similar to Super Mario Bros 3. We already created Egg McGuffin items to get to world 0.

How do you plan to end this game in a suitably climactic fashion? With so many characters and levels and so many game mechanics, people are going to want one hell of a grand finale…

I don’t know. I really don’t know. I would love for world 0 to be able to reuse most of what’s in MKF already, but it all depends on what the other devs create for the world. I don’t think there’s any way for it to match the original expectations that were set for world 0.

Do you ever worry the game might not live up to the hype upon completion?

Absolutely. The original story for the game was hyped up way too much to the point that expectations for world 0 and the final boss were through the roof. I don’t think it’ll live up to the original hype, but that’s only because I don’t think we should try to. The original ideas for world 0 and the final boss were just too ambitious for a game as disjointed as MKF. Instead, I think it would be a lot more feasible to just see what we have to work with already and try to create something that’s new but still, above all else, fun.


The original final boss plan was a merger of all the game’s villains

For that matter, how much longer do you think the game’s development will take? Another 2-3 years? 5 years? Maybe even 10 or more?

Whenever I give an estimate as to how long it would take to finish the game, I always end up underestimating it. If I had to guess, maybe two or three years or so given how development is going so far, but that’s a generously low estimate. If we had more help with programming or sprite art or level design, that estimate could be lowered. It would also help if I could find a way to contact some of the people from the old forums that haven’t joined the Fusion Fangaming Discord server.

Are you ever worried that Nintendo (or another company) might try and get the project shut down?

Nintendo typically only goes after games that are too similar to what they will or are creating. Personally I don’t think they would go after MKF because of just how many elements from other companies are in it, but I’m not ruling out the possibility of them or any other company sending a Cease and Desist.

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If so, what do you do in that situation? MKF is way too big to remove anything right now…

If I get sent a Cease and Desist, I’m ending work on MKF right then and there. I simply don’t have the time to fight the legal system to work on a fangame.

Still, assuming that nothing will happen there, what’s next for the team? Do you have anything else lined up after MKF is done?

I don’t think Fusion Fangaming is going to do anything collectively after MKF is done. I believe some other people are working on XFR, but I’m not on that part of the team. As for me personally, I might do some fangames and other things after MKF is done, but on a severely smaller scale.

How about indie game plans? We know Judge Spear’s team has gone that route recently…

Making a full indie game either on my own or with a team is something that’s on my bucket list, but so far I don’t have any ideas for one nor do I have enough experience working with different kinds of games. Who knows what the future will hold though…

Finally, what advice would you give a new game developer and why?

Make sure it works. Make sure it’s simple. Make sure you’re not stretching yourself thin. See my answer for the things I’ve learned from working on MKF.

Yeah, that seems like good advice to us. After all, Mushroom Kingdom Fusion itself is only in the situation it’s in because of overambitiousness and feature creep. If they’d stuck to a basic plan, and made sure the core characters and mechanics worked first, the game would probably be in much better shape by now, and likely not have taken more than a decade to get to the point it has.

So Keep It Simple Stupid. Don’t get carried away with adding every new idea and feature you have to a game or project, and keep your expectations in check overall. That way, when the project inevitably turns out to be more complex than you think (which is almost always the case), you won’t be stuck with a decade long slog between you and the project’s final release date.

And as Dooki51 says, don’t be afraid to cut things too. If a mechanic or level or character doesn’t work, then you shouldn’t keep them in your game. It’s better to have a fun, stable game where everything fits together well than a bloated, overly ambitious one filled with buggy features and questionably designed content.

Either way, thanks to Dooki51 for the amazing interview, and we hope that with his help, Mushroom Kingdom Fusion can finally be finished in the foreseeable future. It’s been a long time coming, but it seems the end may finally be near for the world’s most ambitious fan game. Here’s hoping for a completed version in the next few years!

Still, what do you think? Do you think Dooki51 can finally finish Mushroom Kingdom Fusion? Will this legendary fan game actually ever see the light of day in its complete form? What did you think of his answers about the game and its development cycle as a whole?

Tell us your thoughts on the matter in the comments below, on the Gaming Latest forums, or on our Discord server today!

Dooki51 on Social Media