Here is the full list of all 38 Toki Tori achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Collect all ten snowflakes that appear in December before they melt
Finish all hard levels
Complete all Bubble Barrage hard levels
Find her.
Stand in the beam in Test Lab bonus level 2
Stand in the beam in Test Lab bonus level 6
Complete all Test Lab normal levels
Watch the ending
Complete all normal levels without using the Wildcard
Complete all Bubble Barrage normal levels
Complete all Slimy Sewer hard levels
Suck up 30 slugs
Collect 1000 eggs
Complete all Slimy Sewer normal levels
Use 42 InstantRocks™ to finish a level
Trap 30 ghosts
Complete all Creepy Castle hard levels
Collect 500 eggs
Complete all Creepy Castle normal levels
Get really close to a monster
Telewarp directly into lava
Trap Toki Tori between two Switchbricks
Find the Tunnel of Love
Complete all Forest Falls hard levels
Finish Forest Falls, Bonus 3
Stand in all sun beams
Freeze 50 monsters
Play Toki Tori for 60 minutes without being idle for more than 2 minutes
Collect 200 eggs
Finish a level without using all items
Make Toki Tori look sad
Collect 100 eggs
Stand on an ice block for 12 seconds
Press "Try Again" 10 times on one level
Make Toki Tori dizzy
Use 32 bridges to finish a level
Fall into the lava
Complete all Forest Falls normal levels