Sometimes, a game can sell me on its name alone, and with a name like Paranautical Activity, I'm definitely listening. This is a roguelike first-person shooter boasting voxel graphics and some really cool designs.
Set on a haunted ship, this run-and-gun shooter randomly generates rooms and features that old roguelike staple -- permanent character death. It's currently in beta, and is available to purchase on Desura for $5.99. It's also hoping to get itself a Steam Greenlight release.
With it still being a work-in-progress, you might want to wait before sinking your dubloons. I'd at least keep an eye on it, though. I certainly like where it's heading.