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.
Like a big family
Another time another opportunity
Can't compete with the trees
What lies beyond
Downwards is the new upwards
Resting by the pond
It was never meant to happen
Collecting the fourth artifact
Don't fight the flow
Curiosity is key
Collecting the third artifact
Collecting the second artifact
Slipping through the cracks
Collecting the first artifact
Falling is not an option
How did they get it up there