Kill 50 enemies using melee attacks.

This is a straightforward trophy, just kill 50 enemies with your melee attack. To use your melee simply press the button, this will hit the enemy with your whip. Repeatedly hit an enemy with the melee attack to get his life down and finally kill him. If you are trying to melee an enemy who has more health such as an elite then try to soften him up with gunfire first.