I agree, you can consider any game you play to be too short if you just blaze though it trying to reach the ending. Like SMW, you can reach Bowser's castle in under 13 stages I believe, but there are 96 exits to find. I've had Wario Ware for over a week but still haven't unlocked all the mini-games, or beaten the high score on Sheiriff. Plus, who can resist the hilarity of Jimmy's disco dance!
Spill the blood of the innocent!!! Then clean it before it makes a mess!