Here is the full list of all 137 Putrefaction 2: Void Walker achievements.
Find twenty seventh secret
Find twenty sixth secret
Kill 4 enemies with 1 dynamite explosion
Complete fifth level of the campaign
Pick up grenade launcher
Deal with jetpack squad
Find twentieth secret
Complete fourth level of the campaign
Defeat enemies near the bunker entrance
Find seventeenth secret
Pick up mp40
Complete third level of campaign
Kill the rock boss
Kill all enemies in the blood chamber
Defeat group of enemies at sector 1
Complete second level of campaign
Kill all enemies on level 2
Defeat last group of enemies before the temple
Kill 2 enemies with 1 shotgun shot
Kill enemies near the town center
Pick up dynamite
Complete first level of campaign
Deal with guys from cave near the road
Defeat tribes after picking shotgun
Pick up shotgun
Find third secret
Complete first level on hard difficulty
Complete first level on extreme difficulty
Complete second level on hard difficulty
Complete second level on extreme difficulty
Complete third level on hard difficulty
Complete third level on extreme difficulty
Complete fourth level on hard difficulty
Complete fourth level on extreme difficulty
Complete fifth level on hard difficulty
Complete fifth level on extreme difficulty
Find first secret
Find second secret
Find fourth secret
Find fifth secret
Find sixth secret
Find seventh secret
Find eighth secret
Find ninth secret
Find tenth secret
Find eleventh secret
Find twelfth secret
Find thirteenth secret
Find fourteenth secret
Find fifteenth secret
Find sixteenth secret
Find eighteenth secret
Find nineteenth secret
Find twenty first secret
Find twenty second secret
Find twenty third secret
Find all secrets on level 1
Find all secrets on level 2
Find all secrets on level 3
Find all secrets on level 4
Find all secrets on level 5
Kill all enemies on level 1
Kill all enemies on level 3
Kill all enemies on level 4
Kill all enemies on level 5
Deal with guards of the green rune
Upgrade player health to maximum
Upgrade player armor to maximum
Upgrade player speed to maximum
Upgrade player ammo capacity to maximum
Upgrade player energy to maximum
Complete wave 1 in survival
Complete wave 3 in survival
Complete wave 6 in survival
Complete wave 10 in survival
Complete wave 12 in survival
Complete wave 15 in survival
Complete wave 17 in survival
Complete wave 20 in survival
Complete wave 22 in survival
Complete wave 25 in survival
Complete wave 27 in survival
Complete wave 30 in survival
Complete wave 32 in survival
Complete wave 34 in survival
Complete wave 36 in survival
Complete wave 38 in survival
Complete wave 40 in survival
Complete wave 41 in survival
Complete wave 42 in survival
Complete wave 43 in survival
Complete wave 44 in survival
Complete wave 45 in survival
Complete wave 46 in survival
Complete wave 47 in survival
Complete wave 48 in survival
Complete wave 49 in survival
Complete wave 50 in survival
Achieve novice rank in timed survival
Achieve apprentice rank in timed survival
Achieve fighter rank in timed survival
Achieve experienced rank in timed survival
Achieve veteran rank in timed survival
Achieve deathbringer rank in timed survival
Achieve unstoppable rank in timed survival
Achieve godlike rank in timed survival
Find twenty fourth secret
Find twenty fifth secret
Find twenty eighth secret
Kill all enemies on level 6
Find all secrets on level 6
Complete sixth level
Complete sixth level on hard difficulty
Complete sixth level on extreme difficulty
Defeat second boss
Destroy 50 energy balls with pistol in the boss fight
Find twenty ninth secret
Find thirtieth secret
Find thirty first secret
Find thirty second secret
Kill all enemies on level 7
Find all secrets on level 7
Complete seventh level
Complete seventh level on hard difficulty
Complete seventh level on extreme difficulty
Find thirty third secret
Find thirty fourth secret
Find thirty sixth secret
Kill all enemies on level 8
Find all secrets on level 8
Complete eighth level
Complete eighth level on hard difficulty
Complete eighth level on extreme difficulty
Complete main campaign on any difficulty
Complete main campaign on hard difficulty
Complete main campaign on extreme difficulty