Love KHUX but IPhone 4 crashes

I absolutely love playing KHUX its fun and Im already putting in a lot of hours into the game. I would put a lot more in but I am experiencing a lot of crashes in the game. Right before I go on quest, and during quest which makes the game hard to play fluidly. I sometimes cant pass a quest cause it will always crash when I fight a boss or particular heartless and this ruins my flow and progress with the game. If this can be fixed I would easily rate this game 5 stars. Im will keep pushing through the crashes cause I love KH

Fist of Death about KINGDOM HEARTS Uχ Dark Road