Complete the tasks during gameplay to get the GamerScore.

Hands-On - GamerScore 10:
Get 5 Grapple kills.

Shish Kabob - GamerScore 10:
Impale an enemy.

Slice 'n Dice - GamerScore 10:
100 Dismemberments.

Chained Attacker - GamerScore 10:
Combo Counter reaches 100.

Parry Farm - GamerScore 10:
Perform every Parry kill move.

Free Fall - GamerScore 10:
Kill an enemy by Death Fall.

Man Handle - GamerScore 15:
50 Grapple kills.

Parry Assassin - GamerScore 15:
100 Parry kills.

Mob Massacre - GamerScore 15:
Kill 5 or more enemies simultaneously.

Parry King - GamerScore 20:
200 Parry kills.

Now You See It, Now You Don't - GamerScore 10:
Disarm an enemy.

Chain of Fools - GamerScore 20:
Combo Counter reaches 325.

Treasure Hunter - GamerScore 20:
Find 50 Treasure Chests.

Death Grip - GamerScore 20:
Get 250 Grapple kills.

Chop Shop - GamerScore 20:
Get 500 Dismemberments.

Meat Market - GamerScore 30:
Get 1000 Dismemberments.

Death Rain - GamerScore 30:
Kill 100 enemies by Death Fall.

Fatal Touch - GamerScore 30:
Get 500 Grapple kills.

Enemy Appetizers - GamerScore 30:
Impale 100 enemies.

Master Looter - 30:
Disarm 100 enemies.

Rock of Ages - 30:
Kill 100 enemies by Boulder Throw.

To unlock the cheat modes which are greyed out at the 'Cheats' menu and can't be selected you must first complete the game on a certain difficulty setting (to play 'King' difficulty you must first beat the game on 'Hard' difficulty.

Unlock Master ALL Moves Mode:
Complete the game on Normal Difficulty

Unlock Song of Death Mode:
Complete the game on Normal Difficulty

Unlock Armour Power Mode:
Complete the game on Hard Difficulty

Unlock Invulnerability Mode:
Complete the game on King Difficulty