Here is the full list of all 59 Looking for Aliens achievements.
Eat 100 food items
Earn every achievement
Collect every collectible card
Find all collectibles on all levels
Find every object on level 25
Level 25 tasks complete
Find every object on level 24
Level 24 tasks complete
Find every object on level 23
Level 23 tasks complete
Level 22 tasks complete
Find every object on level 22
Find every object on level 21
Level 21 tasks complete
Find every object on level 20
Level 20 tasks complete
Level 19 tasks complete
Find every object on level 19
Find every object on level 18
Level 18 tasks complete
Find every object on level 17
Level 17 tasks complete
Find every object on level 16
Level 16 tasks complete
Find every object on level 15
Level 15 tasks complete
Level 14 tasks complete
Find every object on level 14
Find every object on level 13
Level 13 tasks complete
Find every object on level 12
Level 12 tasks complete
Find every object on level 11
Level 11 tasks complete
Find every object on level 10
Level 10 tasks complete
Find every object on level 9
Level 9 tasks complete
Find every object on level 8
Level 8 tasks complete
Find every object on level 7
Level 7 tasks complete
Find every object on level 6
Turn on 50 monitors
Level 6 tasks complete
Find every object on level 5
Level 5 tasks complete
Tap 100 humanoids
Level 4 tasks complete
Find every object on level 4
Turn on 10 monitors
Eat 10 food items
Find every object on level 3
Level 3 tasks complete
Find every object on level 2
Tap 10 humanoids
Level 2 tasks complete
Find every object on level 1
Level 1 tasks complete