Music was deafeningly loud at startup, not sure if that was a problem on my end or yours, but it fixed quickly. >_>
Day/night transition was super smooth and nice. Love the music and sound design. The interface took a few clicks to figure out, but not too bad. I think icons on the bars in the upper left would help clarify which is which, more than simple color, although the color choices make sense.
A neat 2D survival game. :)