This was cute. I know they're not really alike, but the underground feel and the torches gave me a mincraft sort of vibe. I really liked the simplicity of the background art as well. Lots of really nice animations here as well, I was particularly impressed with the boss grabbing and throwing me. I also like the damage numbers, they're viscerally satisfying.
The two things that bothered me was how fast the fall speed was and that I couldn't seem to damage the boss? Maybe I was missing something, I fought him twice and died both times without seeing a single damage number pop-up.
Otherwise, very solid entry!