This Level is 1 of 5 of the Justice League Story Missions, and this is a unmissable achievement as it’s for natural story progression.
Level 16 - “Granny Knows Best”
*** Spoiler - click to reveal ***This level is very short compared to the main story levels and has no confusing puzzles to tackle, you have a short 4 heart Boss (Grail) to defeat which you will need Green Lantern or equivalent to him and then level is over.
As soon as the cinematics cut in pop achievement unlocked.
Congratulations
Happy Hunting