Braid, the Indie-Classic, has already been available DRM-free for Linux for a long time (e. .g on the Humble Store).
Now you can also get it on Steam for Linux.

Description:

Braid is a puzzle-platformer, drawn in a painterly style, where you can manipulate the flow of time in strange and unusual ways. From a house in the city, journey to a series of worlds and solve puzzles to rescue an abducted princess.