The graphics are really cool, so are the explosion and particles flying all over the place, that was fun. However the framerate gets really really low when you have a big wave of ennemies coming for you.
To addup to the camera issue previously discussed in your comments, I believed a fixed top-down camera might be best for your game, it doesn't really follow the character, it feels like the camera is doing whatever it wants to do haha. Also when you are close to the wall, it sometimes goes outside of the level and you can't see anything.