Here is the full list of all 16 PLANET ALPHA achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
It was never meant to happen
Collecting the fourth artifact
Another time another opportunity
Like a big family
Curiosity is key
Don't fight the flow
Can't compete with the trees
Collecting the third artifact
Slipping through the cracks
What lies beyond
Collecting the second artifact
Downwards is the new upwards
Collecting the first artifact
How did they get it up there
Falling is not an option
Resting by the pond