Achievements:ACHIEVEMENT – HOW TO UNLOCKExterminator (10 points) – Defeat the giant spider.Sharp Shooter (10 points) – Do not use more than 30% of your bullets.Unstoppable (10 points) – Finish a zone without losing a life.Lair Slayer (10 points) – Complete all underground zones.Annihilator (10 points) – Kill more than 85% of the total enemies in a zone.Small Arms Expert (20 points) – Finish a zone without using grenades or nukes.Twin Medal (20 points) – Finish a zone in Co-op mode.Speed Freak (20 points) – Finish a zone in less than 15 minutes.Peace Maker (20 points) – Finish a zone killing less than 50% of the enemies.Tricked Out (20 points) – Max out all of the vehicle power-ups.Survivor (20 points) – Finish a zone killing 60% of the units on foot.Assault Hero (30 points) – Complete the game.