Here is the full list of all 12 Inch by Inch achievements.
Climb into the fridge.
Never touch the floor, when your size is 3 feet (91cm) or less, on "Professor" difficulty.
Win a game on Scientist difficulty or above, with only 5% of time left.
Win a game on Scientist difficulty or above, using the Reverter twice.
Win a game without picking up any objects except ingredients, on Scientist difficulty or above.
Start at the floor and reach any of the tabletops, when 8 inches (20cm) or smaller.
Get trapped inside a boot.
Win the game on "Professor" difficulty.
Win the game on "Intern" difficulty.
Win the game on "Scientist" difficulty.
Win a game on "Scientist" difficulty without running.
Complete the tutorial.