The game is really good.
I enjoy the system, maybe as other reviews, check the shop items, how they generate.
For the playing, system works well, lots of fun working out a tactic, but I needed a bit stronger monsters sooner and as other players already said, the second Boss, this red dragon with "22/22" comes very sudden. So there is a huge gap. Bosses should be difficult, that's what makes it fun but the change is way to sudden and for the second boss, way to heavy.
All in all, however it is a nice game which really gets you fixed, once you play a bit more than 5 min.