I was having fun on level 9 or 10 yesterday, and i found a place where you could drop down in a SMALL area with an ogre, i tried that 5 times and died every time, since i had no space to run when the ogre charged me.
5th time I jumped down, I landed on the beastie, killing it

I didn't notice if it gave XP, but it did drop a hammer.
So with a lot of luck, you can actually kill mobs by falling on them
