Here is the full list of all 20 Afterfall: Reconquest Episode I achievements.
Go through all the stairs at the Gate
Do 40 rolls
Finish the game
Finish all available quests
Find all secret locations
Kill 3 enemies with one Shrapnel's shot
Kill 12 enemies with a bounced Shrapnel's bullet
Use Shield to absorb damage that would kill you 9 times
Get 25 headshot kills while using a Shield
Get 7 lives by draining the enemies
Barely survive the combat
Kill 50 enemies using a melee attack
Kill 100 enemies using a machine gun
Get maximum level at Shrapnel skill
Get maximum level at Shield skill
Get maximum level at Drain skill
Using explosives, kill 15 enemies at once
Find all loos at Gyula Creek
Get killed by a lake
Get killed by a train