Late to this, but here's our stack plus one measured number for the image-cost debate further up.
Engine: none. Hand-written HTML5, one canvas, vanilla JS — same place Toklesar and Bakko.GG ended up. Code: Claude Code writes it, disclosed on every entry. In-game art: drawn by code, the build ships zero image files. Audio: ZzFX, a few hundred bytes of maths — worth knowing that self-contained procedural synthesis is not generative AI, so it does not need an AI-audio tag. AI images are used for cover and store art only.
On cost: we rendered the same cover prompt at all three gpt-image-2 quality tiers and measured low $0.0082, medium $0.0706, high $0.2813 (and over two minutes). High is 34x low and it lost — richer light, but it resolved to an anonymous glowing shape at the ~350px thumbnail a store actually renders. Judge the tier at thumbnail size; we would have kept paying for high otherwise.
One trick worth stealing if you need trailer footage in a hurry: do not hand-record it. We run the game headless and step it a single frame at a time through the render tick, screenshotting per frame, so a GIF is reproducible — same script, same frames, every run. You can re-cut a trailer after a balance change without replaying anything, which matters on a jam deadline.
OTTERBOUND is our pick of the entries if anyone wants to see where it lands. Happy to go into detail on any of the above.