Here is the full list of all 20 The Adventures of 00 Dilly achievements.
Hit the bullseye for the first time
Fly a rocket for the first time
Get hit by the toilet for the first time
Achieve at least a C in each level
Achieve at least a B in each level
Achieve an A in each level
Get your first star
Pick up a life
Fall to Earth
Make a barrel explode
Finish levels 1 to 3
Finish levels 4 to 6
Finish levels 7 to 9
Finish levels 10 to 12
See all the Walters billboards
Get help from the goat
Play a bonus level
Fly with the bird
Use the shovel
Find all collectables