A clean and respectable game with a broken system
First of all I really gotta complement you on how well polished this game is. The designs and music are charming and the world (though simplistic) fits its sleeve well. However the games biggest flaw rests in its most interesting content.
The battle system is an interesting take on The 4 Warriors of Light system, but the AP gain makes the game crazy easy. Dumping everything into defense makes the entire game a cake walk save for the final boss. If I could recommend something, make AP cost higher and/or nerf defense a little. Other than that it's an engaging hour waster. Keep at it.