Here is the full list of all 19 GoNNER achievements.
You completed the Cave world. Good job.
You jumped on 20 enemies in a row
You got a combo of 15!
It's not even ASCII, how can it even be called Roguelike???
You got a combo of 5
You picked up a glyph!
You completed the Robot world. Impressive.
You completed Shooty world! Smooth!
You became Death.
you found sally
You completed Death world! Woah!
I'm a serious adult person and I think this kind of humor is childish and should be banned.
I believe in you, get back up.
These combos are just getting ridiculous...
You hit the glyph cap!
You pushed that big piece of trash off your lawn. Good on you.
There's nothing there! No easter egg, no extra item, no nothing. Just a dumb achievement.
Didn't have to skip death.
Did you just run out of colors?