Honestly, I was about to say something similar to Hamdogu before I read his comment.
Having towers share range if they're close enough together is absolutely genius, and is a fresh new mechanic for the tower defence genre, which is great! I do find the mechanic a tiny bit OP and perhaps you need to cap the amount of towers a tower can share it's range with, but otherwise it's great!
Other than that, I think Hamdogu pretty much covered what I was gonna say, wave counter, scoring, the music stopped playing for me as well, cute graphics, etc. But overall, I think you did a good job with this game! Keep it up!