can anyone tell me how I can get through this level??
The easiest way to beat the Goblin Chief is to run at him throwing fire seeds. After about 3 or 4 hits, he dies. When he dies, the stone door behind him opens, go through the door and get the Tree Trunk spell, after that, use Tree Trunk to get up the wall. That's the best way I could put it.
Have the lambs stopped screaming yet?
Also try to jump off the ground when he comes down from one of his jumps. Otherwise you are temporarily immobilized.
Something I found useful: There's a little place right between where he lands and below where the knife is thrown, if you can get some nice destruction goin' on