Try to play mahjong with the robots.

Jump 500 times.

Wear the paper bag.

Meet B-12.

Assume command of the Order.

Pass the Research Facility without killing a Blind One on the DEAD CITY level.

Kill 30 enemies with Crossbow.

Alyosha doesn't get wounded.

Stand your ground against the Bear at first encounter.

Complete the CASPIAN level.

Use the bucket lift on the CASPIAN level to reach the Oasis.

Kill 50 enemies with the Bukhanka.

Kill 3 enemies using sniper scope while wearing the Gas mask and using the Night Vision goggles all at the same time.