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