9. Trials HD (Xbox Live Arcade)
Quite often, XBLA games offer a more casual gaming experience; as a result, you can usually clock a game in its entirety in a handful of hours. Not Trials HD though, which is a Trial Bike game presented through exaggerated physics. With 35 courses of sheer mayhem, ranging in difficulty from beginner to extreme, Trials HD may take up more of your time and energy than you initially thought it would.
Why Youll Never 100% It: With only 300gs worth of achievements within, youd be forgiven for thinking that you could 100% Trials HD in a couple of lazy afternoons. However, there is a particular achievement, Marathon, that requires you to complete the Ultimate Endurance Tournament (which contains 20 levels) without a single crash known in game as a fault. Suffice it to say, this is a monumentally difficult task and for this reason alone, youll most likely abandon your quest for 100% before it even really begins.