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