Max hearts was there as a sort of control to not stock up to many hearts in the easier levels. Regardless I did toy with keeping track of that for scoring, but decided against any form of "high score" for this game.
the other "Game modes" were just a bit of story flavour to tease with. Making 3 more entire games on my own would have been too much in the time I had :P.
Glad to hear you beat the game though :). Helps balance out those who struggled with the controls completely and found it to hard.