Ah, so this is what a Steam sale feels like. Neat! You can pick up Trine 2 and twenty other Linux native games during the Steam Autumn sale.
Trine 2 is a sidescrolling game of action, puzzles and platforming. You play as one of the Three Heroes who make their way through dangers untold in a fantastical fairytale world. Physics-based puzzles with fire, water, gravity and magic; Wicked Goblins; Climb the tallest trees and towers in the enchanted forest! Join your friends in the adventure: Trine 2 has online co-op.
Trine 2: store.steampowered.com/app/35720/
Linux Native Games: store.steampowered.com/search/#os=linux&advanced=0&sort_order=ASC&page=1
Steam Autumn Sale: store.steampowered.com/