Well, this is just amazing! Really, just great how you managed to put such simple idea into an addictive game using different interactive blocks. It is probably the best entry I've played so far and would love to see even more of it. The graphics, sound, music... it all just fits together so well :)
The only thing I struggled with a bit was the direction of the arrow since I couldn't see the mouse pointer where it was being aimed. Would be interesting to see this on mobile as well.