English please? And better hit bars, game is very broken please fix.

Where do I begin?

The shift key is not a good choice for a computer game, you will get a "sticky keys" message if you press it too many times.
Every time you slash, the camera shakes. This will make some people feel nauseous.

The moving controls on this are not WASD like you said in the description, they are the arrow keys.

There is no way to restart the game after you die (except refreshing the page), there should be a button that you can click to take you back to the title screen at the very least.

With the fighting, the hit detection is practically non-existent. When you punch/kick in the air, the enemy's health goes down. But when you are near the boss, you can barely do anything against them.

The ending is just a single drawing without context. At least have a "the end" somewhere.

Overall if this game is a demo, then it needs some serious work if you want to make it a decent game.

The enemy's attacks have no hints or anything, so it's basically impossible to dodge. I can't figure out how to kill him. The way that the slash makes the screen jump is extremely annoying. Energy recharge and punches are way too ineffective/slow to actually be usable.

The art is OK, and it's not a bad concept, but this is essentially unplayable.