Here is the full list of all 5 A long Time achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
It's been a long Time, but we're done now.
That is a Clock? I can't even see the end of it!
Time bends and stretches. Yes, this counts for Clocks, too.
You fell and respawned. You don't have time to fool around. Look at the angry red Clock.
You entered a very strange room.