Here is the full list of all 28 Sweet Pea achievements.
Meet the pop berries
Getting started
Why not have another?
We're not in Kansas anymore
Leave some for the rest of us
This shouldn't be here
Nowhere to run
You get a pass this time
Hold this for me
I'm not okay with this
With great power
I'll see myself out
Should've been faster
Wish I had gills
The trail we blaze
We're going to need a bigger boat
They own the sky
There's nothing there
Better off dead
Down with the Signus
Boss ahead
The deep south
This could be paradise
A simulation inside another simulation
It's just a jump to the left
Your crime was being in my path
Be sure to bring more souls
You found the things