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