Here is the full list of all 23 Serious Sam 3 VR: BFE achievements.
Complete any level in cooperative with at least 2 players.
Use the Mutilator to surf after a Werebull.
Kill an enemy using the Mutilator.
Smash 20 Kleers with the Sledgehammer.
Blow a Major Biomechanoid into pieces.
Solve the riddle of the Sphynx.
Kill 5 Cave Demons while they're in air.
Gib 20 enemies from close range with a shotgun.
Rescue professor Stein. So to say.
Kill at least 5 headless kamikazes in one explosion.
Find Sam's classic outfit
Complete the game in single player on unmodified serious difficulty.
Complete the game in single player in the estimated time on each level.
Awake the Guardian of Time.
Start the car.
Kill a Witch-Bride of Achriman.
Kill 20 enemies with the Minigun without releasing the trigger.
Power up the Timelock.
Find at least 10 secrets in single player.
Defeat the spaceship.
Secure the bird.
Decipher an Egyptian text.
Complete any level in single player.