Dino X Jumpo!
This game was inspired by Google Chrome's dinosaur jump game that shows up when you cannot connect to the WiFi. It was programmed in Z80 assembly, specifically for the ZX Spectrum 48K machine, but it should theoretically work on the 128K speccy as well.
You can play this in single player, and even multi-player mode (thanks to Yuhan).
To play the game, you need the Fuse emulator. Once you have that, change the Makefile line
FUSE=<location of your fuse emulator binary>
and then just run make main in the top-level directory, and you will be playing the game!