Here is the full list of all 26 Melissa K. and the Heart of Gold Collector's Edition achievements.
Finish five hidden object games in less than 20 seconds each
Finish three hidden object puzzles with 100% accuracy
Write 30 diary pages
Find the hidden pea…
Finish 10 puzzles in the adventure without skipping one
Gather 200 objects in hidden object games
Make a 10-combo in the final door puzzle
Lose the final door game 10 times
Touch the rat at least once…
Finish all puzzles in the highest difficulty mode
Watch each cinematic and dialogue screen from beginning to end without skipping
Release and cure all of the game's animals
Finish all hidden object games with 90% or better accuracy
Finish all hidden object games without using a single hint
Collect all the secret letters
Collect all the Reclining Buddha statuettes
See all videos, view all extras, finish all extra puzzles and find all hidden objects
Beat all the best scores
Finish the main adventure
Finish the Collector's Edition adventure
Travel back and forth five times between the same two locations
Send the Gecko to 10 places he won't go
Complete five hidden object games without using a single hint
Gather 50 inventory objects
Use 50 or more hints
Explore 12 different locations