Really enjoyed that for what it was. The power up system was the coolest part where the slimes get upgraded. Would love to see that expanded and made mmore clear, but it was a ppleasant surprise when my purple on started wrecking fools. The rats were a bit scary for a first enemy because they were so fast. all around cool concept.
You also might want to try switching the GOOOOO text to CLICK TO START or something like that becuse i didnt realize that was how you began.