From the Steam Store page:
Out of the blüe, we’ve updated our first IGF award-winning game! GoNNER BlüEBERRY EdiTION adds new weapons, heads, enemy types, a new challenge, some sweet, sweet, new visuals. And yes, there are also blüeberries.

Hop back into GoNNER if it’s been a while! And if you lose your head, it’s cool—we have plenty more where that came from.

GoNNER is a tough as hell score-based procedurally-generated platformer with roguelike elements. GoNNER is also a story about friendship between Ikk, Death, and a space whale named Sally.

You will die. A lot. This is by design, but it's not made to feel unfair. You'll eventually get the hang of GoNNER, so don't lose your head. But even if you do it's okay cause we have a lot of replacement heads you can use.