Wonderfully simplistic. Although the luck kinda cheapens it a bit, it is also fairly addictive, and the "hard" badge is really mostly luck and not skill, but that aside still fun to play 3.5/5 (voted 4/5).
The game was fun at the start, but after like 20-30 minutes you can easily get into a comfortable rhythm that allows you to beat the game without ever feeling nervous even. I failed on almost all my 70% or lower missions and still managed to win easily.
If your making a sequel make it a bit harder, but aside from that no real complaints!
I don't see why everyone seems to think this game is so hard. When you level up you heal slightly. His attacks are not hard to dodge besides the one where he glows but the damage on that is small.
The last 2 gems have a glitch where if you grab 1 it shows on the stat screen that you have the other, but as far as upgrades are concerned you have the one you picked up.
Only problem I see is a little short a bit easy (if you can beat normal you can beat master almost for sure). And not enough diversity with Limit Breaks.
 "Bloody Fun Day"){kind=icon}
 "Mastermind: World Conquerer"){kind=icon}
 "The Savior"){kind=icon}