I was playing Lava World (Insane) online with friends. We got to the area where you need to be beefy to remove the metal, we did that and then proceeded to kill the enemies above. After they were all dead I somehow managed to get stuck on the point where the top of the ramp flattens out (top in terms of elevation and top side of the ramp). I couldn't get out at first, it would let me move but I will still stuck on an invisible line. Eventually I was able to somehow move off the platform and into the lava and come back down.

I don't think this can be exploited, I didn't try at least, but should be fixed.

EDIT: This was on the PS3 version.