Comment by finalarbiter

This is a good list, and there are some games on here I've never heard of. That said, I would suggest the addition of Xonotic[0] to the 'first-person games' category, and Luanti[1], formerly MineTest, to the 'sandbox games' category.

[0] https://xonotic.org

[1] https://www.luanti.org/en/