Become a true ranger.

Complete the game in Spartan Mode.

Kill 5 amoebas.

Kill at least one enemy with each weapon available in the game

Explode 30 enemies.

Use a Medkit 75 times.

Get 30 kills with Hellbreath.

Kill a librarian.

Kill 50 Watchmen.

Drink at every occasion.

Kill 30 human enemies with headshots.

On the level OUTPOST reach the radio tower and broadcast the commander's message.