The frog in the arena was easy. Just time your stuns and silence it, you'll beat it in 2-3 minutes. The game has a really slow start which makes it quite boring, and too easy near the end which also made it boring. Only fun I had was during the mid games where things weren't too easy or too hard. I'd enjoy it more, if it had some puzzles or secrets you can solve to unlock side-stories or mini-bosses to challenge.