I hate. I Hate! I HATE!!
This game is a grade-A Jerk-Bag!
First off, the controls; you can't go down on the over-world, regardless of weather or not there is actually a platform there.
Second; Flappy bird?
Third; Every time you slay a demon, the results screen shows your remaining lives and then pulls a world class troll by not giving you an extra one which would be very helpful because it is unreasonably easy to die, lives are in limited supply, and there is a very small life cap.
Fourth; Flappy bird!?
Fifth; There are some levels (I'm not gonna call them enemies or bosses) where you can't see the teeth (which kill you instantly, taking away your very limited lives) until it's already too late. This is what I, as an aspiring game developer myself call "Forced difficulty through bad game design."
and Finally; FUCKING FLAPPY BIRD!?!?