This was my entry for #LOWRESJAM2018.
I am posting it here to share it with the pico8 community, and effectively "open source" the result. Feel free to remix and poke around. I've had to remove most of the comments to make it fit in the cart limits. But most of the code should be pretty self explanatory, there's nothing super fancy besides the generator and some efficient reuse of "render object" functions under the hood. The cart is nearly full, so you might need to do some serious memory hacking or make some code somehow more efficient in token use to make new AI/features. But graphics and tile layouts are all your playground too.
Since the chunk generators are based on parts of the tileset map data, even a newbie can have fun changing those and playing the results.
Let me know if you remix it into anything awesome, and enjoy! :)