I love pretty much everything about this game, from how the levels gradually get more difficult, to how different monsters will do different things to inconvenience you. I only have two minor problems, they're not much of problems, but, at the title screen, it was the slightest bit difficult to navigate through the options. Of course you'll immediately figure it out because the most obvious buttons that would select something on the title screen are space and enter. But it would be nice to just have something on the title screen saying, "PRESS SPACE TO SELECT," or something similar to that. And the second thing is that the title screen seems very empty, maybe you could just add some sort of image as a background.
(Again, I know those are minor problems.)