Anyone who uses mascot knows that levels are made of tiles. Wall tiles, slope tiles, corner tiles... But there aren't any tiles with two opposite corners.
So what happens if, using crunch tiles, you get into a situation where one of those would be required?
Simple. It'll destroy a second crunch tile. And it doesn't care if that second 'crunch' tile isn't a crunch tile. Which tile is the second destroyed one depends on which tile is destroyed to create said situation.
You can use this to either create one-chance passages in mascot, or find embarrasing BG tileless areas, I can't think of anything else this could be useful for. But it's still cool.
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"Hee hee... hee hee hee... I've seen them. I've been there. Hee hee... I've seen behind those masks they wear. They're just like us... don't you know? Just... like us... It's hopeless! Hee, hee. You might as well give up!" -Babbling Habnabit