I picked this one up in the tower defense fest, and have found it to be pretty fun. It's EA still, but it's effectively a finished game - there's a new biome and a few characters to add, but I would have been happy with what's there at the moment as a full game.
It's kind of a combo of tower defense, roguelike and tetris - the RNG is tempered though, you always have access to all your collected towers, it's only the tetris blocks that you maze with that are random draws each round.
Pros: Colorful, fun, good variety of maps and mechanics, creative multi-phase bosses, wide range of towers.
Cons: Balance needs work - the merchant and tiny-bot are stronger individually than all of the other characters combined. It's single player though, so you can take the character class as an extra difficulty setting ;p
The winter biome's zone effect is obnoxious as hell too - this may not be a con if you like having an extra complicating factor in your building.