From the campaign:
Gruff is a tactical combat card game where players duel to the death with custom teams of Mutated Monster Goats! Gruff features unique positional and timing mechanics that create a constant state of attack and counter-play.
Rage of the Trolls provides the same visceral competitive experience as Gruff and Clash of the Battle Goats, but adds a new dimension to the game, Troll Boss-Fights! The troll is a challenging puzzle that players will take on individually, or with a friend in a co-op mode! Rage is a stand alone Gruff-Compatible game which means that players can take on these trolls using just the contents of this box, or by adding cards from other Gruff games as well!
The campaign is closing in on 2.5x funded, but there's only 8 days left to get in on the action.