Count Downes is a good pun and the game around it is clean and easy to read. The bow tracking the cursor feels right, and getting to pick between speed and health after a wave gives the run a bit of shape. Healing to full between waves is definitely the right call for something this short. The theme is where it's thinner for me. A wave that happens to count backwards doesn't change how I play, so the countdown ends up being decoration rather than pressure. I also hit a bug worth knowing about, when I died partway through wave 2 the Enemies Remaining counter dropped to minus one, so something keeps ticking after the wave should be over. Worth a look, since that number is the one bit of UI carrying the theme.