Here is the full list of all 17 GONNER2 achievements.
You beat a big dumb bird, uh, okay.
You beat a big dumb computer, hmm, alright.
You beat a big dumb squid, yeahh, mhm.
You beat a big dumb face, ew, oh well.
You beat granny, what a twist.
Your mind is somewhere else during this, I can tell.
That's a lot of robots.
Ditto says hi.
That's a low combo.
That's an okay combo.
That's a high combo.
That's a higher combo.
That's an insane combo.
That's a nice combo.
Beat the game without that place where the brain lives.
Guns are uncool anyways.
Well done