At first, I didn't understand that I had to leave in order to win, so on my first playthrough I got all the moths but just roamed around until the mothmonster got me. Then on my second game I saw the ladder, so I wouldn't say it ruined my experience, but I think it should be more clear that you have to leave through the ladder.
On the other hand, very good ambientation! I also liked the graphics and the monster design, it just lacks a bit of sound effects. Nice game ;)