Here is the full list of all 35 Quell achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Collect every jewel
Take twice as many moves as necessary
Take over 10 minutes to complete a level
Complete a level in under 5 seconds
Use the ring 5 times
Push 10 blocks
Push 2 sets of blocks together
Retry a level 20 times
Get stuck in a loop 5 times
Spiked 20 times
Be spiked 10 times
Be spiked 3 times
Die on a first move
Play for 1 hour
Play for 30 minutes
Play for 10 minutes
Complete every Quell level in perfect moves
Complete a shelf in perfect moves
Complete a stage in perfect moves
Complete 40 levels perfectly
Complete 20 levels perfectly
Complete 10 levels perfectly
Complete 3 levels perfectly
Complete every Quell level
Complete the 1945 shelf
Complete the 1943 shelf
Complete the 1941 shelf
Complete the 1939 shelf
Complete the 1937 shelf
Complete the 1928 shelf
Collect 200 pearls
Collect 150 pearls
Collect 100 pearls
Collect 50 pearls
Collect 25 pearls