Developer ports 1987 game Sidewinder to the browser using Claude Code and Opus 5.5

A developer posting as dmassena on r/gamedev says he brought Sidewinder to the web using Claude Code with Opus 5.5. He co-created the game with Hayes Haugen and Jonathan Sposato. His goal was to let people play it without an emulator or hunting for ROMs. The result is playable at sidewinder.darrinm.com. This is a self-reported account, and we have not independently verified it.

The source material was messy. Aside from startup, the 1987 game is written entirely in 68000 assembly, about 17,000 lines across 32 files. He pointed the agent at a folder of partial original source, a pirated disk image and unfinished ports to other platforms. He asked for a modern WebGL version that stays faithful to the original but uses AI-remastered art and sound. He added a few pointers and a fal.ai API key, then went to bed. By his account, the game was fully playable with music, blasters and explosions the next morning.

He rates the research, planning and code highly. He says the agent dug through archives, source and ports, ran emulators, recorded reference videos and split the disk image into files. It also specified undocumented file formats. He judged the code by whether it worked without bugs, not by how optimal it was. The whole job took a few hours and, he says, did not make a dent in his Claude plan.

The remastered art needed fixes. A sprite-upscaling process had a bug, and tile-grid drift was bad enough that he regenerated the backgrounds with gpt-image-2.5 flare, a model Opus had not tried. The remaster also broke the game's color cycling, the old-school palette-animation trick. He describes both problems as easy to fix by prompting.

The weakest areas were audio and typography. He says LLMs cannot hear, and that the agent can convince itself it made a good sound when a human listener would hear a tone, not an explosion. He also says Opus cannot meaningfully tell glyphs apart, so asking it to find a font matching an image is guesswork. For anyone trying a similar project, his account suggests that audio and fonts need human review, while the code and research steps largely ran on their own.