Tron is a great game for fitting into a very small space. Back in high school I spent a lot of time optimizing Tron on the TI-82 to fit in as few bytes as possible. It looks like I got it down to 152 bytes: (only about 80 bytes of actual Z80 assembly code)

https://www.ticalc.org/archives/files/fileinfo/227/22747.htm...