Summer of Arcade bonus title Crimson Alliance is available now on Xbox Live Arcade.
It comes free if you've bought previous games From Dust, Bastion, Insanely Twisted Shadow Planet, Toy Soldiers: Cold War and Fruit Ninja Kinect.
If you haven't, you can still download it for free, but players are charged for each race they want to play.
There are three to choose from, available for 800 Microsoft Points each (about £6.80).
The Wizard Class Pack gifts the user magical combat capabilities, the Assassin Pack adds stealth, while the Mercenary mixes in swordplay.
Alternatively you can buy all three for 1200 Points (around £10.20) and switch between them at will.
Crimson Alliance is a co-op heavy dungeon-crawler with Torchlight-esque visuals. Development is headed up by Certain Affinity - ex-Bungie staff who've recently collaborated on maps for Call of Duty: Black Ops.