Minecraft is always great. Or the free Luanti.
No idea how powerful that card is but everything up to Quake 3 should work. Maybe more. Unreal Tournament 99 and 2004 are free now and can be found on https://oldunreal.com/.
You don’t need Steam but it makes buying and installing games very easy. But you can also buy games on https://gog.com/ and install them with Heroic. It’s more or less as easy as with Steam.
Or you can just look through your distributions software repository. It should have plenty of free games.
In the end it really depends on what you’re looking for. “Games” is a vast field.


















Play Portal 1 first. It’s not very long but still great.