Reached the terminus.

Reached the other side.

Took a breather.

Blow up the tunnel and airlock at CURSED STATION.

Kill 100 enemies with shotguns.

Kill 30 human enemies with headshots.

Wipe your Gas Mask 20 times.

Kill 10 Enemies in a row without taking any damage.

On the level HUNTER kill the nosalises before they break through the ventilation grilles.

Collect all 32 Golden Cubes and 32 Anti-Cubes.

Reactivate all 5 warp gates.

Find the Counting Cube artifact.

Find the Writing Cube artifact.