EDIT: I now recommend the LLVM-MOS build, it both conforms to the LoROM spec and runs at full speed everywhere, unlike the vbcc build which had a couple slowdowns.

For controls, swap "B" and "Y" in the emulator to keyboard buttons "C" and "X" respectively.

Full demake/rewrite of pico 8 celeste in c for the super nintendo, mostly complete, because it's an a complete rewrite, it runs at 60fps with a 256x256 world as opposed to 30fps 128x128, written entirely in c. As such the physics while similar feeling, are distinctively different to the original.  I think this stands as a testament that is in fact possible to write snes games in c, and have them still be performant. Being a demake some creative liberties are taken, like reinterpreting the cloud effect and making the screen shake only apply to the distant objects in the background, separated out as it's own layer.

I recommend the vbcc build because it runs faster, however the Calypsi build is the one that fits the strict rules of the Jam being LoROM, I couldn't figure out how to get VBCC to output a valid LoROM file. Should probably mention that while this is written in c, it's not using PVSNesLib, instead it's using a derivative of my original pure C demo files from my experiments with wdc816cc.

Known Issues and thoughts:
Sometimes loading a new level isn't completed correctly and the graphics end up in a glitched state. Level 12 has the most actors with collision and suffers from slowdowns. The only two compilers supported are VBCC and Calypsi, early dev versions were built using wdc816c, but given it's strict c89 requirement and the fact that it generates code slower than both calypsi and VBCC I see little reason to re c89 the entire codebase. I tried writing a simple audio driver for the spc700 using LLVM mos, very simple demo's worked, but there are a handful of issues with the compiler that are beyond the scope of this project but I suspect that in the near future it will be possible to write the audio code in c as well. I suspect that if LLVM mos ever ends up supporting the 65816 this will be able to run at full speed without a problem. 

There is no compression applied to level or tilemap data whatsoever, things are just stored directly in the rom uncompressed and it still comfortably fits within the 256kb requirement, with the sa1 I'm confident the speed problems could be alleviated and the game would also be able to run at 60fps. 

Special thanks to svambo for testing on hardware before the deadline.

Code available here

https://github.com/Phillip-May/snes-homebrew/tree/master/snes-Celeste