So far the only part of this game I've found stupidly frustrating was the Skeleton Caves. I died a good eight times right before the save point before the boss against the two T-Rexes guarding it, because I only had about 36 hit points by then, and I could never avoid getting hit at least ONCE. Eventually I kept collecting hearts by refreshing rooms, and wasted them away with glyph unions. The boss, afterwards, was easy.
Some other areas kicked my butt as well, but not to the point of screaming rage.