The game is fun. I would have used more the "break fake walls with the hammer" mechanics. You do that once in the first stage and then the hammer just becomes a weapon of mass destruction.
The revealing shield platform mechanic was ok, the problem is that i've seen that so many times by now that it has become boring, but it's not your fault.
The melee combat was good overall. In the first part it's really hard to damage the enemies without getting hit, especially the boss before the shield.
When you pick up the hammer it becomes easier but I noticed that the hitbox of the flying hammers is a bit broken sometimes, I found myself hitting an enemy and not making any damage.
Also a visual feedback for the player's invulnerability span after you've taken damage is needed.
The jump right after you pick up the lighter shoes is hard for no reason in my opinion, the one where you have to jump forward and then come back in mid air. I get the point that you have to demonstrate the new feature to the player but the big jump right after was more then enough to show it.
Overall the fights were balanced well and I liked the progression of the game.
I think the voice dub for the game is cheesy, if you're not an actor maybe a solid text with a cool looking font is better.
The music was good and the sound fx too.
Nice game!