1.) I think having some areas be harder to navigate would be interesting- like how someone else said: make the first swamp area a little like a maze would work really well.
2.) Some varied text when picking up a fly would be nice. I also think that the game would work better with a larger map - more pathways leading to different rooms with different challenges on how to obtain the flies.
(also, is the middle left fly in the second room supposed to be obtainable?)