Here is the full list of all 19 Celerity achievements.
Complete the tutorial
Complete the Sea area
Complete the Sky area
Complete the Neon area
Complete the Wallrun Challenge
Complete the Grappling Challenge
Complete the Hookshot Challenge
Complete the Bubble Jump Challenge
Die 100 times
Retry 250 times
Enter the Freeroam mode
Acquire the hidden object
Wall jump 1500 times
Grapple 1000 times
Hookshot 500 times
Bubble jump 250 times
Use jump pads 250 times
Use speed pads 100 times
Rail jump 100 times