There was a good premise but... there are some problems, mainly:
-you can't die.
-the pixel art look blurred, try setting the "filter mode" of your pixel art textures to "point" instead of bilinear.
-I can see the light blue background on the sides, and there is a small gap between the bottom of the monks' sprites and the ground.
-there is no challenge (you just place the mouse at the left of the tree and click), which makes it boring. It could be solved by making enemies come from all directions, or have the player click them 3 times, etc. (really, these are examples, you can do anything you want, the sky is the limit!)
I'm sorry to be so critic about it, (given that you made it under that time limit is quite impressive), but I thought I should point it out.