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