One time I was playing Pikmin, and I walked to the back of one of those pipes with the bomb rocks in them, then some kind of giant glitchy polygon thing came out of no where and the game lagged so hard that a huge chunk of my Pikmin just disappeared because the game couldn't handle processing them anymore.
So some random high-poly thing overloaded the RAM and cleared a majority of your Pikmin to combinsate? Bummer.