Loving the game, but I have some major gripes...
1)  Capcom likes to kill off Zack...I mean, come on, some of the deaths are absolutely ridiculously trial-and-error...
2)  The walking-around controls...I was killed multiple times in the bastardly Keeper of the Ice and Frost Breath levels because Zack walked somewhere other than where I was aiming at...Thankfully these times of need have been fairly infrequent, but it's still frustrating...
3)  The music mini-games...I hate them...HATE THEM... 

Other than that, I love the puzzles (when they aren't trying to kill you in a cheap way), love the music, love the characters, love the visuals, and love the theme...Very nice stuff...