Full list of all 25 Serious Sam 3: BFE achievements worth 250 gamerscore. It takes around 15-20 hours to unlock all of the achievements in the base game.
The base game contains 20 achievements worth 200 Gamerscore, and there is 1 DLC pack containing 5 achievements worth 50 Gamerscore.
Complete the game in single player on unmodified serious difficulty.
Complete the single player campaign.
Find at least 50 secrets in single player.
Complete the campaign in cooperative with at least 2 players.
Awake the Guardian of Time.
Power up the Timelock.
Kill 20 enemies with the Minigun without releasing the trigger.
Kill the kicked enemy while it is still in the air.
Decapitate a Khnum.
Perform all possible finishing moves in the game.
Rip Scrapjack's head off.
Kill an enemy using the Mutilator.
Solve the riddle of the Sphynx.
Blow a Major Biomechanoid into pieces.
Secure the bird.
Smash 20 Kleers with the Sledgehammer.
Rescue professor Stein. So to say.
Complete any level in single player.
Kill at least 5 headless kamikazes in one explosion.
Find Sam's classic outfit.
Win 10 deathmatch games.
Win a versus match.
Complete the Jewel of The Nile single player campaign.
Make at least 3 kills in one Instant Kill match.
Score a total of 10 points in CTF matches.