Interesting take on the theme, but I feel like the difficulty level wasn't high enough to make you engage with the gimmick.
I got to wave 14 with no issues, just putting money into Speed and Full Heal, then kiting the enemies around the corners. I feel like adding some scaling to the full heal would make death an inevitability much sooner as you aren't guaranteed a fresh start every wave, and encourage the player to take more risks. At the moment there's no reason NOT to take the full heal every round, and - as dying wasn't a threat - putting money into the enemy didn't feel like a real choice.
Otherwise, I thought it was pretty decent. Music was good, theme use was good. Didn't find any obvious bugs. (though the 'try again' button didn't work for me for some reason, nothing impacted the actual gameplay)