256 simpler games
In the 1980/s, Stephen Wolfram began considering and experimenting with elementary cellular automata. These are, instead of a 2-dimensional grid, just a one-dimensional row of cells or squares. At least one of these simpler games, rule 110, turns out to be Turing complete, just like Conway’s game of life.
Here are links to more information about rule 110.
Here’s a link to the online atlas of elementary cellular automata.
Here’s a link to Stephen Wolfram’s book on the subject.
And last but not least, here’s a link to a page about an experiment, that includes some cellular automata you can listen to. The active cells have been mapped to notes on a musical scale.