Here is the full list of all 38 Quell Reflect achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Complete a level in under 6 seconds
Collect 25 pearls
Collect 50 pearls
Collect 100 pearls
Collect 150 pearls
Collect 200 pearls
Complete the 1962 tutorial shelf
Complete the 1964 shelf
Complete the 1967 shelf
Complete the 1970 shelf
Complete the 1972 shelf
Complete the 1974 shelf
Complete every level
Complete 3 levels perfectly
Complete 10 levels perfectly
Complete 20 levels perfectly
Complete 40 levels perfectly
Complete a stage in perfect moves
Complete a shelf in perfect moves
Complete every level in perfect moves
Complete a level requiring 2 drops
Complete a level requiring 3 drops
Complete a level requiring 4 drops
Spiked 5 times
Spiked 15 times
Get stuck in a loop 5 times
Retry a level 10 times
Push 4 sets of blocks together
Push 10 spikes
Merge drops 3 times
Spike a poisoned drop
Break 15 gold blocks
Break 3 gold blocks in one level
Sacrifice a drop in order to continue
Poison 2 drops in order to continue
Use the ring 10 times
Close 50 gates
Collect every jewel