I have purchased every single open source game that I’ve seen listed on steam as paid. Examples:
- Shattered pixel dungeon (and also the original Pixel Dungeon)
- TOME
- Shapez
- Open Hexagon
- Mindustry
- Lugaru
- Mega Glest
- Marvellous Inc
- Hydra Slayer
- HyperRogue
For more FOSS games on steam, there’s a decent list collected on this curator (also pointing which ones are only partially open): https://store.steampowered.com/curator/38475471-Libre-Open-Source-Games/?appid=1769170
Bash. By default it might seem less featureful than zsh… but bash is a lot more powerful and extensible than some give it credit for. It might be more complex to set it up the way you like it, but once you do it, that configuration can be ported over wherever bash exists (ie. almost everywhere).