Really liked the intro and the game premise is hilarious, good job! Upgrading my knife with an axe was unexpected and pleasing. It also changes your approach to killing enemies, which adds variety.
In my opinion what this is lacking is the trajectory line, that would show how far you will travel. Just like in golf games - you get the hit strength meter (which you have) and a visible line of where will the ball travel. That would certainly help with planning your movement, because at times i miscalculated my trajectory and was forced to see my roomba slide helplessly.