Really great game! Loved variation of the enemies which allowed for strategies (e.g. the yellow ones were a MENACE at the beginning, but once I figured out the right placement they were easy to beat).
One problem I had was collection of pills/money. From what I understood the cursor was too small and difficult to find, plus collecting each of the pills individually becomes a bit of a tire especially when the de-spawn time of the pills is so short
Also the waves seemed to stop ramping up after a while? Perhaps it needs to ramp up faster?
A last thing might be the injections, I wish they had some sort of clear labelling so I knew what they did!
Otherwise it was a really good game and would love to see more done on it!