Last month, I wrote an article talking about how AI is mass decompiling/recompiling/modding all sorts of games. Since then, I decided the best way to truly understand what's going on... is to try it myself! I'll be talking about my experience using Claude Opus to remaster a childhood favorite of mine, Eets. If you just want the end result, skip to the conclusion.
Eets is a neat puzzle game where you try to lead this weird creature to the finish by adding obstacles and food that changes its behavior. It's also the very first game made by Klei, who went on to make some bangers like Don't Starve, Mark of the Ninja, and Oxygen Not Included.
Anyway, the game recently got re-listed and made to work on modern PCs, which is great! However, it still leaves a lot to be desired... the game runs at 30FPS, has a maximum resolution of 1024x768, and for some odd reason is stretched to fit the screen with no setting to change it back to its original 4:3 aspect ratio. Let's fix all that.
My goal for this experiment is figuring out three things:
- How hard is it to make Claude fix the game?
- What's the process like? How many times do I have to intervene or manually fix something?
- How does Claude make it work?
I got a free week of Claude Pro from a friend (thanks again) to test as much as I'd like. I'm going to try and put as little effort as I can and see what Claude dcan figure out on its own. From what I can tell, most people are doing the same thing.
I opened the game files and put in my first prompt in Claude Code:
This is a game called Eets. It's hardcoded to work at a low resolution and is capped at 30FPS. Make the game work at 60FPS and at a native resolution.
Claude kept automatically churning out code and "testing" by opening and closing the game. It's honestly stressful to me that I'm just leaving an AI agent to play around on my system and take screenshots. The only saving grace is that it asks for my input before running dangerous commands such as removing a file. Still, the whole process leaves a massive question mark on how private/secure this actually is. I already had a weird moment where it accidentally screenshot my whole desktop while researching AI for something else.
<sub>Yes, I definitely want this thing to take control of my computer without supervision</sub>
25 minutes and ~150k tokens later, it was finished. The end result is a folder with some tools and, mainly, a c file. This file has a lot of incomprehensible glue code to hook into the game's renderer. I could ask Claude to leave comments and give better names but that's not the point right now.
<sub>I'm not going to pretend I know how this works</sub>
I opened the game, and everything seems to be working! The game still runs at 30 physics frames per second, but all the movements are interpolated to 60fps to give it a smooth feeling. It's noticeably nicer to play.
The game looked the same though, because even though it now runs at a native resolution, the assets are all low quality and blurry. The game is also still being stretched to widescreen, which is inconvenient.
Add an option in the game's options menu to enable or disable stretched widescreen. Then, upscale the text and 2D assets to be sharper in high resolutions.
Again, I'm impressed by how much it's able to do without any kind of input. It added an option to enable/disable widescreen which I guess isn't surprising anymore, but it figured out how to upscale the assets without asking anything. Claude automatically downloaded Real-ESRGAN's cartoon model (a good choice considering the game's flat art style) and started upscaling every single asset and animation with it.
The results aren't perfect, some images have a tiny bit of artifacting around the outline, but from what I can tell the original assets also have this problem. The important thing is that the art style is exactly the same, and the upscaling model isn't "adding" any detail that isn't there.
<sub>High quality animation of Eets going 🤨</sub>
Claude takes a while and kept opening/closing the game every minute or so, but the end result is that it just worked. It's still mind boggling to me that this is possible, and yet we've all become desensitized to AI in merely a few years. When I excitedly told a friend that this worked, the response I got was "yeah, it can do that" in a normal tone.
The results are very good when compared side-by-side. To keep the comparison fair, I made the remastered version stretched even though this is not what the game is supposed to look like.
I asked Claude to do a few more small changes, such as allowing the windowed mode to be resized and maximized (previously impossible because the game was stuck at 1024x768), and optimizing some of the PNGs it spat out earlier.
<sub>This is what Claude Code looks like on the terminal</sub>
Here's a video of the end result! I recommend fullscreening it to see the differences more clearly.
The result speaks for itself. The game is significantly sharper and much smoother to play while keeping the core intact. Like I mentioned last post, I think this has pretty great implications for game preservation. I'm sure everybody has come across it by now, but there are decomps/recomps for all sorts of old abandoned games, enhancing them and making them work flawlessly on modern PCs.
To answer my earlier questions...
How hard is it to make Claude fix the game?
Very, very easy. It suddenly makes a lot of sense why so many people are creating game recompilations without understanding what they're actually doing. Frontier models can do it automatically.
What's the process like? How many times do I have to intervene or manually fix something?
It's a lot of waiting around while Claude opens and closes the game to test. The biggest part of the process is manually testing the game yourself and mentioning any issues for Claude to fix. You also need to be explicit in what you want it to do, such as telling it to upscale the textures or add a certain option.
I tried Claude for other projects too (which I'll maybe make another post about), but I never had to manually fix anything. It does well on its own.
How does Claude make it work?
Unsurprisingly, a fair amount of code that hooks into the game. It decompiled the game to understand what the code does, then started improving the game by interpolating movements to 60fps and replacing textures with upscaled versions. The actual physics of the game is unchanged and still runs at 30 ticks/second, so I don't have to worry about any differences in gameplay.
It also created a separate binary to run the remastered version rather than replacing the game's original files, which is good.
I'm not going to upload my remaster of Eets by the way, that was mostly for educational purposes. I put little effort into it and haven't tested it for more than an hour, so I'd rather wait for someone to do it properly than add to the spam of half-baked remasters online. For now though, I'll enjoy the game for myself!