Here is the full list of all 19 GoNNER achievements.
You completed the Cave world. Good job.
You got a combo of 15!
It's not even ASCII, how can it even be called Roguelike???
You picked up a glyph!
You got a combo of 5
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 jumped on 20 enemies in a row
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?