I loved the idea, it's pretty damn interesting and it makes hearts nearly omni-purpose, which is a theme I like a lot (So much so we made our jam game all around near-omni-purpose mechanics!), and it's allright to not focus on aesthethics that much, specially since the visuals aren't like, horrible, they're just simple.
But you've got a few game design issues there, mainly level design and the fact therea re no checkpoints. It's kinda frustrating to wait for health every time, and the second level kind of frustrated me a bit too much. Not because it's hard? but mostly because it takes too much time and it's kind of annoying, but you already know that, and that's a HUGE step towards an even better game!!
I overall liked it a lot though, uses the theme really well in my opinion!