Earn Power Points from a Troll
Trolls are vulnerable to daylight. Wait until a troll comes out of a cave, and shoot at it with a ranged weapon (like a bow and arrow). The troll will immediately freeze. Continue to shoot at it for a while to earn many power points.
Eliminating Large Armies
First, build up a defense to protect your fortress. Obtain several Murkwoods, and equip them with Silverthorn arrows. Place the Murkwoods next to the fortress so they can guard it. Add the Arwen, Glorfindel heroes and three to five groups of horses to form an army of allies. Fully upgrade the heroes and horses skills, and place them in the back of the enemy base. Your army of allies will easily defeat large enemy armies from this location.
Unlock the Hadhood, Maur and Idrial Characters
To unlock the Hadhood, Maur and Idrial characters, complete specific levels in the "Good" campaign along with all bonus objectives. Levels needed to unlock these characters: Hadhood (Level 1), Maur (Level 4) and Idrial (Level 8).
Unlock the Krashnack, Olog and Thrugg Characters
To unlock the Krashnack, Olog and Thrugg characters, complete specific levels in the "Evil" campaign along with all bonus objectives. Levels needed to unlock these characters: Krashnack (Level 1), Olog (Level 4) and Thrugg (Level 8).