My hands are in pain but the adrenaline rush is more than worth it. Incredibly fluid movement, fun gunplay (partially due to the movement), plenty of fun exploration and secrets, and incentive to perfect each stage leads this to be one of the most addicting games I've ever played. It requires you to learn its mechanics in each stage and will regularly test you with its boss fights and in-level challenges. Multiple difficulties also add to this game's massive replay value. Cannot recommend enough.