Here is the full list of all 19 Lost Pixel achievements.
Booted up Lost Pixel
Finish level 1
Finish level 2
Finish level 3
Finish level 4
Finish level 5
Finish level 6
Finish level 7
Finish level 8
Finish level 9
Finish level 10
Finish level 11
Finish level 12
Finish level 13
Finish level 14
Finish level 15
Play for 10 minutes in one go
Play for 20 minutes in one go
Play for 30 minutes in one go