Sheer Brilliance
This game has the cleverest physics-based puzzles since Half Life 2 and the proceeding episodes. At first, I put the game down for more than a year because I thought the game lacked depth. Boy was I wrong. After playing past the second level, I discovered that you could level up your character, specialize in abilities, and equip different items. This game soon became everything I wished it to be. The levels are varied, extremely well designed, and most of all, just plain fun.