Here is the full list of all 12 Lucidity achievements.
Complete all Bonus Levels
Act II completed
Collected 1000 fireflies
First Level Completed
Act I completed
Act III completed
Collected 100 Fireflies
Collected 500 fireflies
Collected 1500 fireflies
Collect all the fireflies in 'Every Kite Soars' in a single run
Beat 'Deep Sleep Dive' without collecting any fireflies
Beat 'All Around is Petrified' without taking any damage