Here is the full list of all 20 35MM achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Reach the finals with a partner
Die
Listen the airwaves in the hospital
Listen the sound anomaly at the first location
Reach the finals alone
Open the safe in the city
Find a room with mannequins in city
Kill all dogs without reloading weapons
Listen to the radio signal in tunnels
Find anomalous zone in the tunnels
Find the secret documents in the safe
Rate the abstract picture on location "Bor"
Find "easter egg" from the first game of author
Give your partner a first aid kit
Call to Hell
Assemble the children's puzzle
Help to grandfather in town
Find the bodyes of hanged people over the railway
Kill grandmother in the old village
Light a candles in an abandoned church