I have been playing Time Snatcher Handy recently, a roguelike centered around a time-stop mechanic, which only uses 44 MB. It is pretty good.
Going through my steam library from the lowest up, here are the others i would recommend, stopping at one GB, because most of my games are under 20 GB and i tend to be relatively selective with what games i get so i consider most of them good also:
TIS-100 (80 MB), programming puzzle game by Zachtronics
Islanders (150 MB), minimalist city builder
Enter the Gungeon (346 MB), bullet-hell roguelike
Streets of Rogue (417 MB), roguelike which emphasizes having multiple possible approaches for how to get any given objective
Opus Magnum (493 MB), another Zachtronics programming puzzle game
Vault of the Void (554 MB), roguelike deckbuilder (one of my most played games, especially recommended)
Backpack Hero (616 MB), roguelike focused on maximizing adjacency bonuses on your inventory grid
Urbek City Builder (685 MB), city builder (obviously)
Slipways (735 MB), a game about optimizing trade routes between planets
Cassette Beasts (1 GB), similar to Pokemon, with the main differences being that you turn into the monsters instead of summoning them, type advantage/disadvantage giving unique status effects rather than just changing damage and battles generally being 2v2 instead of 1v1
I have been playing Time Snatcher Handy recently, a roguelike centered around a time-stop mechanic, which only uses 44 MB. It is pretty good. Going through my steam library from the lowest up, here are the others i would recommend, stopping at one GB, because most of my games are under 20 GB and i tend to be relatively selective with what games i get so i consider most of them good also: