This game could be great, but there are couple of things that grate me: 

Waiting for the energy to refill is tedious as hell, & the whole while I have to constantly feed, clean, & play with my Digimon. Said Digimon likes to randomly throw hissy fits over nothing, destroying all the "friendship" I've painstakingly developed over the last 3 hours.  Why do I get such a gut punch when I was playing the game properly? I click the ball they kick the ball, repeat. That's what I was doing, but they flipped out.