has anyone heard of minetest? Its basically an open source minecraft-like game (no, its not full minecraft, its more like pre 1.6 minecraft) which is super easy to mod (because it uses a Lua API for modding, also its main intention is to be for modding) and its free, and it can run easily on a potato. super cool and I made the beginning of a tech mod in like 4 hours which was mostly just me figuring out how to use the API and making textures in paint dot net
I played it once