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