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