You should add some recovery time after you got hit for otherwise if you get cornered by one or two enemies you die without having a chance to fight back or escape.
It froze two times for me. Looked up in a walkthrough, so I got sure that I didn't miss anything. The second time the whole screen got frozen and I couldn't even "restart" the scene.
The battles where you can't decide which unit you want to summon or which spell to cast but get everything from the conveyor-belt-thingy get freaking cheap in the later game. Jeez, it's more luck than everything!
Same problem as beeble2003: Level 5 and cannot pass the gate. For i had not saved when i has the chance after the last level i think i have to restart the whole thing and start all over from stage 2. Seriously, this is bull shit!
The puzzles are sometimes a pain in the arse: I think you should be able to solve the puzzle once you figured it out. But here you have to fiddle all parts in exact the right spot to get the ball into the bucket. That's quite annoying.