(I was going to post this in the gaming section but that's meant just for tablet games, whereas this topic is more general.)

I've been trying to assess the state of the open source gaming world, but it's quite difficult to do because most lists of open source games consist almost entirely of games that are either clones of commercial titles, puzzle games or unfinished.

Are there any open source games which are original, not puzzles and relatively finished? I don't mean former commercial games either, but games that were written from the very beginning as open source titles.

The reason I'm interested is because open source versions of applications such as word processors can be very close to their commercial counterparts in functionality, or even surpass them. But open source games seem a lot further away from commercial quality.

Am I wrong? I'd love to be wrong about this so please do post if you can correct me.