Here is the full list of all 30 Sheepy: A Short Adventure achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
You lit all the crystals!
You finished the game without dying.
The last one?
You beat the game in 45 minutes.
You beat the game in 30 minutes.
You finished the game.
... is awaiting you.
You listened to all the tapes.
Wait, another Sheepy?
I know this place!
But now you can fly.
You showed Patches who's the boss.
Almost done!
You're a smart one, aren't you ?
You can do it!
Run as fast as you can.
GOTTA GO FAST
Archaeologist is a dangerous job.
You have activated the 6 levers.
The third one!
BABY, RIGHT 'ROUND
It feels nostalgic here.
Such an engineer.
The second one!
"Your estimated wait time is forever."
You made a new friend!
"Taking You Higher"
Something happened here...
The first one!
...but no you can't, because you're a sheep.