Very solid tower defense game!
I played a lot of the early BTD games on flash websites when little, this brought me right back. Particularly, the way every part of the ui is on screen and updated in real time, including cheekily placed volume settings, really reminded me of that whole era. The number keys for selecting towers is also a nice touch.
The wave design is pretty aggressive, it took me multiple tries to get to the boss, and the boss music felt pretty fitting for getting there.