Just breakout with some cool ideas. Breakout 71
Factorio light. Wish it were a little less stressful at times. Mindustry
Open universe trader, fighter, etc. Endless Sky
For the mathematically gifted (or challenged...) Mental Math
- Because you know you like this. 2048 Open Fun Game
Amazing puzzler. Wish one could save. Tessel
Crosswords. Forkyz
40 puzzle games in one. Simon Tatham's Puzzles
Tricky, unique, polished puzzler. Zoysii
The amount of content and love that went into this RPG rivals commercial games. Andor's Trail
The forever classic. Shattered Pixel Dungeon
Because weird is cool. AAAAXY
There's more (Unciv!), but this should keep you busy for a long while.