Certain translation errors and highly predictable boss patterns aside, this is a highly playable app that also does not flood you with new ads every five minutes. If you enjoy action RPGs, it is worth the time to play through once.
If the later game gives you trouble, just remember these two tips: the bosses have attack pattens that you can exploit after learning them, and your dash attack will give you a few frames of invincibility to dodge otherwise unavoidable attacks.