Thanks for playing and the feedback.
We definitely need to work on the balance. We wanted the last wave to be a kind of final boss battle, so it was meant to jump, but everything up to that should have been building up to it. The music could use some work, with it starting less intense and building up as the difficulty does. We will also look at the default volume in comparison to the SFX, and putting volume controls onto the pause screen. We did debate requiring the player to collect things, but opted for the auto collection for the jam. If we develop this game further, this may change, perhaps adding a new tower for automated collecting.