I liked the game, though my issue with it was that I never had any need to acquire new monsters. Once I filled my team up once, I literally just trained those monsters and they were far superior to anything else I encountered, and pouring points into monsters to level up / evolve them made it feel kind of bad/ like a waste to even consider new monsters.
Otherwise I thought the game was pretty good!
I like the game and its pretty fun though there are a lot of glitches. For example even though I earned and used the hidden monster and got the achievement for beating a tourney with it, the achievement for unlocking that monster never unlocked. The same goes for all the skill related achievements. Kongregates achievements for lvl 15 and beating littlegiant also didn't unlock...kind of disappointing
 "Monster Saga"){kind=icon}
 "Monster Arena"){kind=icon}