Crimsonland (2003) is a top-down shooter that shipped as a stripped DirectX 8 binary with zero symbols. I decompiled it with Ghidra, validated behavior with WinDbg and Frida, and rewrote it from scratch in Python/Raylib — 46,800 lines matching the original behavior faithfully. The write-up covers static and runtime analysis, reverse engineering custom asset formats, and the full rewrite process. Code is on GitHub and it's playable now via uvx crimsonland@latest
Very impressive, makes one wonder what do some companies have in private compared to public tools that we stitch together. E.g. you can combine LLMs with statical analysis/proving to get much better results.
I really need to start familiarizing with these new tools, I'm only using LLMs in interactive, “question and answer”, mode and it feels like using a typewriter when everyone is switching to computer word processors.
Thanks for sharing, it's a really interesting writeup and project!
10tons tends to make smaller scale games and you feel it sometimes but I've had a great time with quite a few of their other shooters too. You used to be able to get this bundle for cheap from fanatical sometimes, not sure if that is still the case. They are best known in the modern era for Tesla vs Lovecraft which doesn't show up in this bundle.
https://store.steampowered.com/bundle/428/10tons_Shooters/
There have been a few attempts to make open source versions of Crimsonland and I had a good time with Violetland
https://github.com/ooxi/violetland
As an active reverse engineer, I'm really curious how you used agetic AI for this! Did you just have them going through the code and labeling stuff? Or were they also responsible for writing the reimplementation? This overview is super interesting, I would love to see details about the pipeline itself.
I don't know anything about reverse engineering, but I have wanted to reverse engineer/decompile the Disney Animation Studio [1] for DOS for years.
I found the software at a thrift store in 2009, when I was eighteen, and I was immediately impressed. This was actually very intuitive, easy-to-use animation software that was very powerful, years before FutureSplash/Flash was released.
There's not a ton of info available on the internet now, but I have been trying to remedy that a bit [2] by uploading the manual. I reached out to Disney to ask if I could potentially buy and release the source code off of them, and they politely told me "no". I reached out to the creators in the credits on LinkedIn to see if there there was any way I could look at the code or if they could at least answer some questions, and they never got back to me.
I think the only way we're going to get the source code to The Animation Studio will be if I learn how to use Ghidra (or something similar) and decompile it myself.
Bravo, that’s a seriously impressive undertaking, and a great demonstration of the augmentation potential in agentic coding. There’s so much focus on replacing entry-level work it gets missed what these power tools can do in the hands of people who know what they’re doing.
Any recommended learning materials/resources for basic binary reverse engineering? I'm imaging a resource that teaches the common tools/concepts and provides binaries in increasing complexity.
I've been thinking about this topic and am glad to see it come up: AI is going to be a huge boon for digital preservation & restoration projects like this. I realized this while building this project (a map explorer for Tribes 2): https://exogen.github.io/t2-mapper/
Old games like this have a small (and shrinking) audience of people who care about them. With Tribes 2, for example, there are only ~50 people who actively play on a regular basis. A subset of those people are programmers, and a subset of those have the time & energy to put into a project like t2-mapper, assuming they're even interested. I got a basic version working, but then Claude Code helped decode and convert obsolete Dynamix/Torque3D file formats (improving existing Blender addons that were incomplete), got TorqueScript running in the browser, wrote shaders, and generally helped figure out what the original C++ code was doing.
In the past, you'd need the stars to perfectly align for stuff like this to happen: a passionate super-fan with the time, resources, knowledge, and persistence to see it through. Now, you mostly just need the persistence (and maybe a couple hundred bucks for tokens). I foresee people with niche interests (but not necessarily a programmer's skillset) being able to extend the lifetime (and maybe audience) of their obscure or obsolete software.
I'd be curious to see if there were any discoveries of any cut features left on the cutting room floor still present in the code [0] (aside from the demo teaser code mentioned still being present). I always find software archaelogy fascinating, as we get scraps of unused content or code, and can only guess as to the decisions made that led to it being scrapped, or why certain custom file formats were used, or code was structured a certain way.
[0] I am aware that such a wiki exists exactly for this purpose.
I only know about this game because it was in some Humble Bundle. Have the Linux version from that. Not sure how old it is. Looks like the screenshot of one of the remastered versions. Remember installing it and playing for a few hours but then forgot about it.
Last Humble Bundle update from 2019, but I can't get it to run on my current Ubuntu. Runs in my Ubuntu 16 QEMU vm, but no audio for some reason.
Pretty much expected level of success for old binary-only Linux games. Can probably be fixed, but usually just playing the Windows version in WINE is easier and plays better.
the version you had is a 2014 remake, it's quite different from the version i've recreated from 2003. this one only existed as for win32. my version should run on linux, and even if it doesn't, it's all open source, so should be easy to patch and have it work forever.
This is a lot of fun! It's the first time i've ever used the uv package manager directly, and it was shocking how fast the game was running for the first time on my machine. Very nice.
Looks like the game still only runs in a small window, but Valve's gamescope*, had it running full screen right away too.
All modern AI tools tend to put `from __future__ import annotations` line into Python code which isn't required by recent Python versions.
I guess this is because they all are trained on an intermediate code bases when this was required some times (even at that time the real usage was quite rare).
And now this line is parroting everywhere like a junk DNA :)
I used to play a lot of Crimsonland, so this is very nice. I thought the updated version that they later released on Steam never captured the original feeling. The newer game is still fun but the older version is better, gameplay wise.
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[ 0.29 ms ] story [ 52.6 ms ] threadGoing to give this a spin after work. Thanks for the work and the writeup!
Thanks for sharing, it's a really interesting writeup and project!
There have been a few attempts to make open source versions of Crimsonland and I had a good time with Violetland https://github.com/ooxi/violetland
https://store.playstation.com/en-us/product/UP4403-PPSA02752...
https://github.com/banteg/crimson
I found the software at a thrift store in 2009, when I was eighteen, and I was immediately impressed. This was actually very intuitive, easy-to-use animation software that was very powerful, years before FutureSplash/Flash was released.
There's not a ton of info available on the internet now, but I have been trying to remedy that a bit [2] by uploading the manual. I reached out to Disney to ask if I could potentially buy and release the source code off of them, and they politely told me "no". I reached out to the creators in the credits on LinkedIn to see if there there was any way I could look at the code or if they could at least answer some questions, and they never got back to me.
I think the only way we're going to get the source code to The Animation Studio will be if I learn how to use Ghidra (or something similar) and decompile it myself.
[1] https://en.wikipedia.org/wiki/The_Animation_Studio
[2] https://archive.org/details/disney_beginner_guide_2/disney_b...
There used to be a Linux version but apparently it hasn't been updated to be added to or even compiled on modern Linux kernels and distros.
Someone I know tried to resurrect it a few years back but now I'm wondering if couldn't use OpenCode etc to get it up and running again.
(I did find a recent-ish clone [1] so may start with that)
0 - https://en.wikipedia.org/wiki/Bolo_(1987_video_game)
1 - https://github.com/stephank/orona
Reversing this by hand seems like it would have taken orders of magnitude longer…
Old games like this have a small (and shrinking) audience of people who care about them. With Tribes 2, for example, there are only ~50 people who actively play on a regular basis. A subset of those people are programmers, and a subset of those have the time & energy to put into a project like t2-mapper, assuming they're even interested. I got a basic version working, but then Claude Code helped decode and convert obsolete Dynamix/Torque3D file formats (improving existing Blender addons that were incomplete), got TorqueScript running in the browser, wrote shaders, and generally helped figure out what the original C++ code was doing.
In the past, you'd need the stars to perfectly align for stuff like this to happen: a passionate super-fan with the time, resources, knowledge, and persistence to see it through. Now, you mostly just need the persistence (and maybe a couple hundred bucks for tokens). I foresee people with niche interests (but not necessarily a programmer's skillset) being able to extend the lifetime (and maybe audience) of their obscure or obsolete software.
[0] I am aware that such a wiki exists exactly for this purpose.
I'm also impressed by the game's jaz image format. Very cool.
Last Humble Bundle update from 2019, but I can't get it to run on my current Ubuntu. Runs in my Ubuntu 16 QEMU vm, but no audio for some reason.
Pretty much expected level of success for old binary-only Linux games. Can probably be fixed, but usually just playing the Windows version in WINE is easier and plays better.
Looks like the game still only runs in a small window, but Valve's gamescope*, had it running full screen right away too.
* gamescope -W 2560 -H 1440 -r 60 -S stretch uvx crimsonland@latest
I guess this is because they all are trained on an intermediate code bases when this was required some times (even at that time the real usage was quite rare).
And now this line is parroting everywhere like a junk DNA :)