Along that line..

• SectorForth - https://github.com/cesarblum/sectorforth - sectorforth is a 16-bit x86 Forth that fits in a 512-byte boot sector.

• TetrOS - https://github.com/daniel-e/tetros - Tetris that fits into the boot sector.

• BootMine - https://github.com/io12/BootMine - Bootable minesweeper game in a 512-byte boot sector

• Invaders game in 512 bytes - https://github.com/nanochess/Invaders

The author has written a book called Programming Boot Sector Games.

> A crash course into 8086/8088 assembler programming, in an easy way with practice at each step. You will learn how to use the registers, move data, do arithmetic, and handle text and graphics. You can run these programs on any PC machine and no program exceeds 512 bytes of executable code!

https://nanochess.org/store.html

Examples from the book: https://github.com/nanochess/book8088