Fun and satisfying! Not sure how it fits with the theme though!
The balancing felt like it ramped up too quickly at the end (I think you're aware of that because you mentioned something similar in your game description). I also noticed that the upgrades/continue buttons' hit boxes were maybe a bit off? I think you could only click on the top half of the buttons, which made them feel like they weren't properly responsive until I realized where to click.
Really nice visuals and sounds.