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