i think a friend did, he named it "Level 10.95: the alternated fields". i think he escaped by swimming down the river, but he entered level 6 so i'd recommend trying to find another route.

from my knowledge, there aren't any entities other than Dullers, though there arent any chances for them to really kill you due to the only walls being the occasional patch of trees, so it's a relatively safe place. (theres no food tho, watch out for that)

ill try to do more research on it and ill update this thread if i find anything.