Here is the full list of all 20 Relive achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Launch a training session
Save the Devs from certain death :D
Complete the fourth Story level
Find all secrets in the fourth Story level
Find all secrets in all levels
Don't be sad!
Yeah, no problem, it's not like you are all going to die or something!
Stay a while and listen
Complete the third Story level
Find all secrets in the third Story level
Not as bloody as you expected
Complete the second Story level
Find all secrets in the second Story level
This stuff works IRL!
You wouldn't download a martian AI
The old school way
Complete the first Story level
Find all secrets in the first Story level
Confirmed... to be your best friend!
At least they didn't fall out of my pocket