That’s certainly the most difficult solo achievement to unlock in the game. Play through the Metropolis level in Serious difficulty, without dying, nor reloading a save.

So, how do we do this?

First, enable Infinite ammo in Custom Options before launching. And yes, this is allowed and won’t prevent the achievement from unlocking.
Second, you don’t need any save or anything. Just launch the relevant level from the single player menu.
And third… We are going to break the level. As simple as that.

You start like this :



It’s impossible to avoid taking any damage at the start. So, just do your best. Take out the Reptiloids last – they can wait, and their projectiles can be easily destroyed. Kill the Kleers, the Gnaar and the other scumbags first.

Be careful when going up this ramp : a Kleer will spawn, as well as some trashmobs. Have your shotgun ready.



Then, you’ll have another 2 Reptiloids and one minor Arachnoid to kill.




After that, do NOT go left – you’ll make another hell on earth spawn. Go right, near the corner, you'll make the rocket jump here.

Just do as I do in this video !

After a looong walk, you’ll be there.



Take the bumper, and you’ll be in the last part of the level. Take the health and armor to heal from your rocket jump, and then ready yourself : you are going to face 4 waves.

Wave 1 : Beheaded kamikazes.

Easy. They spawn slowly, almost one by one. Just take the Tommy Gun, and take them all out.

Wave 2 : Witch-Harpies.

A LOT of Harpies, actually. Be careful to avoid their kicks. Keep using the Tommy Gun, running in circles in the area, and take them out one by one. You can also fire some rockets if they are close enough to each other. Boom !

Wave 3 : Sirian Werebulls. ROCKET JUMP HERE !



Do another rocket jump, to climb on this wall.
Then, just wait. Werebulls will mass themselves just beneath you. Best way to take them out is to fire grenades on this wall, were my cursor is on this screen. Be careful not to fall.




Wave 4 : Major biomechanoids and Kleers.

Just stay on the wall, the furthest possible from the enemies (again, don’t fall :p). Take out the Biomechs first, best with the Laser. Kleers are extremely stupid and won’t be able to hit you (their projectiles will be blocked by the wall). Just keep spamming grenades until they all die.

When sam says “Yeeeeehaw !”, you have won. And that’s it.

The achievement should trigger when you exit the level by going through the door that opens in front of you.



I hope this helped !