For Caverns of Underkeep I’m trying to do as much as I can with ‘programmer art’ and artwork thats in the public domain. For me, it’s more important to get the functionallity correct and in place before the game gets dolled up.

If you’re developing a Roguelike, or maybe an indie RPG and want to get started with some art content you can use The RL Tiles a free set of tiles and monsters.