Simple but creative, satisfying gameplay, clean visuals and audio. Clear thematic direction, everything fits the style. On gameplay:
A "hit" indicator would be helpful, late game I found myself struggling to discern where the enemy had made it to a tree.
I would have appreciated a slight amount of camera control, but that may come down to taste.
Early game is a bit monotonous, I would have enjoyed the enemy spawn rate being a little steeper.
Hi score: 50,000 ish I think?
All said and done, good job, I'd recommend this for a nice little time-killer.