It is a bit difficult to understand what to do in this game. It takes too long for the first enemies to arrive.
A bug (I think): Pressing E seems to always end the game, even if my temperature was above 90 degrees.
A minor point: Sound default shouldn't be at 0%. If you're concerned that it might be annoying to players, use a low volume like 10% or 20%. Most players won't go into the Settings menu until after they try out the game.