Here is the full list of all 70 Serious Sam HD: The Second Encounter achievements.
Complete The Grand Cathedral level on serious difficulty without dying or loading.
Complete the game in single player on serious difficulty.
Frag a total of 1337 players.
Frag 100 different players.
Complete the game in single player by beating estimated time on each level.
Earn gold medals on all Survival levels in single player Survival.
Earn gold medals on all Survival levels in cooperative Survival.
Win a Team Beast Hunt match on all game levels with least 2 players on each team.
Perform 100 rocket jumps.
Win 100 My Burden matches with at least 3 players.
Frag a total of 1000 players.
Win 100 Instant Kill matches.
Win one round in Last Man Standing game with at least 4 players.
Pick up at least 10 extra life items in Cooperative Coin-op game.
Complete the game.
Find all secrets in single player.
Win a Team Beast Hunt match on any level with least 2 players on each team.
Find at least 80 secrets in single player.
Frag 10 players without being killed in at least 4 player Instant Kill match.
Make at least 3 kills in one Instant Kill match.
Find all 3 Cannons in Teotihuacan - The City of the Gods.
Win 100 deathmatch games.
Complete 100 Deathmatches.
Get all 3 Rocket launchers in Palenque - Sierra de Chiapas.
Pick up 100 gold coins in Coin-op Cooperative game.
Kill 100 Harpies with the Sniper rifle.
Win 100 Last Team Standing matches with at least 2 players on each team.
Frag a total of 500 players.
Win 25 CTF matches with at least 2 players on each team.
Win a CTF match with at least 2 players on each team.
Score a total of 100 points in CTF matches.
Earn at least a bronze medal on any level in single player Survival.
Deliver the final blow to Mordekai with the Knife.
Complete the South America episode in single player or cooperative.
Kill 1000 enemies with the Laser gun.
Kill 50 Syrian Werebulls with a knife.
Kill 300 Kleers with the Cannon.
Win one My Burden match with at least 3 players.
Hold the Burden for at least 10 minutes in My Burden match with at least 3 players.
Earn at least a bronze medal on any level in cooperative Survival.
Win a Beast Hunt match on all game levels.
Win a Beast Hunt match on any level.
Complete the Medieval episode in single player or cooperative.
Burn 500 enemies to death.
Complete the Persia episode in single player or cooperative.
Earn a round for your team in Last Team Standing game with at least 2 players on each team.
Win 100 Team Deathmatches with at least 2 players on each team.
Win one Team Deathmatch with at least 2 players on each team.
Frag the same player 5 times in a row in at least 4 player match.
Win an at least 4 player Deathmatch by reaching frag limit of at least 25 without dying.
Perform 4 frags with each being no more than 10 seconds apart from the previous frag in at least 4 player Deathmatch.
Frag all players in a single frag combo.
Win 25 1-on-1 Deathmatches.
Complete a Deathmatch with frag limit set to at least 200. (Frag limit must be reached!)
Win a Deathmatch Marathon.
Frag 25 players with a knife while having no more than 10 health left.
Frag 100 players in a knife-to-knife fight.
Frag 100 players with a knife from behind.
Frag 100 players with a knife.
Frag a total of 100 players.
Frag the same player 10 times during a single round in at least 4 player match.
Win a Deathmatch.
Complete any level in at least 3 player cooperative game.
Complete any level in single player.
Complete a deathmatch game with at least 1 frag.
Find a secret under water.
Accumulate a total of 100,001 enemy kills and frags combined.
Complete a Coin-op cooperative game on normal or higher difficulty.
Win 1000 Deathmatch games.
Win 100 Last Man Standing matches with at least 4 players.