i LOVED zack & wiki in levels as The Crystal Key, The Painted Secret and Mirror, Mirror. Relatively short and very clever puzzles that are fun to complete. The only thing you can do wrong here is mess up your HirameQ ranking, but who cares about that. It gets less fun when the game goes into hardcore trial & error mode. There's this level in the fire world where, if you do ONE thing out of sequence, it's game over... without the game telling you so. If you do something wrong there, it can't be turned back and you have to restart the level yourself. Very annoying. Also frustrating: getting to the end of a level, only to realize you skipped a step (airship level: you didn't blow up the hangar hatch with the cannon? => fail at the very end) or you have no item equipped when a scripted sequence starts (end of jungle level: no umbrella equipped when free falling => death)
Some of the remote implementation is shoddy too, like the fire ball tennis in that one lava level.
Finally picked the game up again yesterday with 15 parts collected, should be near the end now.