Looks like an already well-refined game. You also said what this game is all about in one sentence, what is a good thing.

But ‘get rid of his devilish side’ is hard to imagine. Or too many ways one could imagine. So, from platformer action aside, I am not sure what this game will be about from description and trailer.

The trailer uses changes of scenes and other screens, but somehow lacks some impact. I did not get that ‘I really must play this. NOW!’ feeling. But maybe that’s just me so consider the opinion of others as well. :)

The music is really beautiful and underlines the setting of being in a magical world. Just the action (shooting another) and the peacefull music did not match at that point in the trailer. When the maincharacter was just running around, it matched really well.

I hope that was somehow helpfull.