If your goal is to view sprites or hear sounds:
GameMaker Studio 2 (GMS2) is a popular 2D game development engine. A decompiler for GMS2 attempts to reverse-engineer compiled game files (typically .win, .data, or .wasm files) back into a readable form, often recovering GML (GameMaker Language) code, sprites, sounds, objects, and room data.
Before proceeding, it is vital to understand the ethical and legal implications:
Every GameMaker game includes an implicit license. YoYo Games' own EULA states you cannot reverse engineer, decompile, or disassemble software created with GameMaker.
Ethical Guidelines:
| Scenario | Ethical? | Legal Risk |
| :--- | :--- | :--- |
| Decompiling your own game (lost source) | Yes | Low (no distribution) |
| Decompiling for personal modding (non-commercial) | Gray area | Medium (depends on game dev) |
| Decompiling to learn techniques (no redistribution) | Gray area | Medium |
| Decompiling and reusing assets/code commercially | No | High (liable for damages) |
| Distributing a decompiler tool | Yes (tool itself) | Low (if open-source for education) |
Key point: Just because you can decompile a game does not mean you have permission to use that code.
Several community tools have attempted GMS2 decompilation:
Important note: As of mid‑2020s, there is no fully reliable, public GMS2 decompiler that restores original variable names, comments, or exact project structure, especially for YYC-compiled games.
| Use Case | Legality Risk | Technical Feasibility |
|----------|---------------|------------------------|
| Recovering your own lost GMS2 project | Low (if you own the compiled game) | High (VM builds) |
| Modding a single-player game | Medium (depends on EULA/dev permission) | High |
| Learning GML from compiled games | Medium (but often tolerated for study) | High |
| Cheating in online games | High (violates ToS, possible bans) | Medium (anti-cheat may block) |
| Pirating commercial games | High (illegal) | High (VM builds easily decompiled) |
You can write a custom loader that decrypts the game's resource file at runtime. While a determined hacker can find the key, it stops 99% of casual decompilers that expect a standard data.win.