Thanks to a quirk of Steam's storefront, a deceptively tricky puzzle platformer is now free for you and all your friends.

Come September 13, that update had happened, and the game now had art that matches its two sequels, ran on monitors running over 60Hz, added Steam inputs, and most significantly, now included online ...

Classic Edition is free on Steam forever after its dev made it so without realising they couldn't switch it back.