Hey Ben!
Great job, it's a fun little game to play. One bug I found was the golden heart upgrade didn't work for me. Picking up golden hearts gave no health increases anymore. The mixing of a high resolution font, with low resolution pixel art was a little jarring at first as well. Maybe worth trying a low res font too to see if it fits the game better.
Seems like a good concept overall though, so good luck with your Kickstarter!