Ur stuck in the puzzle tower of death. It's the end for you and ur buddy if u can't think your way out of the dungeons. Avoid spikey things and anything else that will hurt you and try to unlock the iron gates which close off each level.
This is quite a tricky game, as you will have to coordinate your efforts with the other lost soul in the dungeon. Also, aim to collect all the stars within each level to maximise ur points.
If you're killing one of the players again and again, then try the walkthrough to the right, it will help u out.
Get out of the tower before you get eaten by the resident bugblatter beast of traal!