I agree with the commenters below that the game misses some signaling. It very unclear what the effects of your actions were. I also found the the difficulty ramped up too quickly around 100 points, but maybe that is a skill issue.
The fact that towers only scaled temporarily was also very confusing. Wouldnt it be interesting if they were permanently that large? That would require strategic planning for the future, and constantly building out further. You would also have room for multiple upgrades. I see lots of potench, to dig up a reference from some years ago.
Overall, well done!