Here is the full list of all 20 Twinsen's Little Big Adventure 2 Classic achievements.
Get Baldino to upgrade your jet pack
Find one of the two secret rooms in the Gazogem Factory
Acquire the Ball of Sendell
Visit the Emerald Moon
Heal your Dino-Fly
Become a wizard
Make the rain disappear
Learn the Ferryman’s Song
Reach Island CX
Complete the game
Control the crane in the gem mine
Jump through the hoop in the Otringal dog park
Visit the island across the Hacienda and gain the Protection Spell
Kiss the frog on the island of the Wannies
Heal the bowler’s back (warning: his opponent will not be amused!)
Beat Stanley Opar in the Emperor’s Palace
Follow the race car driver on Desert Island
Free Joe from his clam in the Cemetery of the School of Magic
Unlock all items in the game
Collect 500 Kashes