Here is the full list of all 32 Millennium 2 - there are Take Me Higher achievements.
Spend 20+ hours on the game
Play 1+ hour
Finish the game in less than 9 hours in Hard Mode
Create Your Government List
Held more than 30 000 Gold
Repair Gravitron
Tame 30+ Enemies with Jezabel
Pass Gigantine's Lair
Kill Gigantine
Kill Trickster King
Kill 1+ enemy with Piu-Piu
Kill 50+ Enemies with Gravitron's Laser
Kill 50+ enemies with Abu
Kill 200+ Enemies with Abu
Complete 1 quest
Complete 6+ quests
All quests completed
Complete 8+ quests for Dee
Find 1+ secret room
Find 5+ secret rooms
All secret rooms found
Complete the game fully (all quests, secret rooms and animal kings)
Hard Mode Completed
50+ items found
Kill all animal kings
Kill Queen Twin
Kill Zombie King
Kill Ooze King
Kill Scorpion King
Kill Lion King
Kill Gorilla King
Kill Imp King