Warstone TD is an interesting Tower Defense game that includes the additional strategy of a town with lots of unlocks. It also has co-op maps, and multiplayer PvP maps! Grab a friend!
The Wild Eight is a post-apocalyptic survival game. Scavenge, craft, explore and fight - alone, or in co-op with friends! Review written in Early Access.
Dead Exit is a strategy based card game in which you manage survivors and resources. Fight the zombie hordes, alone, against or with other players.
An in depth look at Hex: Shards of Fate, an MtG-inspired collectible card game. I've played this for hundreds of hours and I'm glad to say it's finally shaping up.
A hack n slash action RPG (heavy on the action) with a witty narrator. Tons of replayability and full co-op mode too!