Infiniminer is something that comes to mind - which was the base used for Minecraft, I think. While we're in the Realm of voxel-based games, there's Minetest,

Infiniminer is something that comes to mind - which was the base used for Minecraft, I think. While we're in the Realm of voxel-based games, there's Minetest, which is open Source and written in C++ and extendable by Lua. Iirc, braid was also developed solely by one person, although he did commision the art. But in general, the "big game made by a single person" is a bit of a myth. Sure, it does exist, but many of those people have either had help from others, or were actually working in a small team. A lot of it is just marketing talk.