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