Find the Alma Doll on every Mission
The Dolls spawn randomly! They can be at multiple locations but only one single doll spawns in each playthrough of an interval. Restarting the whole interval will change the doll spawn.
Very Special Thanks goes to the Community of xbox360achievements.org and GHOST59-AD from Playstation Network for showing me several locations.
Interactive Timeline in Video Description! Use it to jump right to the next interval after finding the doll.
In the Poker Room of Prison, kill all 3 enemies with headshots before slo-mo ends
Story-Related and only possible during the very first interval of the game called ‘Prison’. After fighting some guys with rifles you will reach the before mentioned poker room. It’s the place where the game explains you how to use the Slo-Mo.
Find something worth punching!
This is story-related and only possible during the last interval ‘ward’. After destroying the first memory you will find yourself in front of some punching bags. Melee some of them a couple times.
Kill 2 enemies with 1 Slide Kick during Slo-Mo
Important: You have to reach level 2 before getting the Slide Kick ability.
This is one can practically be done everywhere. The first opportunity appears right in the beginning of ‘Interval 01 – Prison’. You will have to use a switch after killing the first two enemies of the game. Two guards will appear at the end of the corridor. Use your ‘Slo-Mo’ Ability and the Melee-Button while running. Try to line them up as good as possible.
State-of-the-Art. Bang, Bang!
Kill 10 enemies in a row with Sniper Rifle headshots
You should play on the lowest difficulty ‘Recruit’. Moreover, a higher personal rank will give you more Slo-Mo time.
The best location to do this appears during ‘Interval 4 – Suburbs’. After fighting some zombies in a cellar a cutscene will start. You will find yourself in a roomy area with a Sniper on a balcony.
Ignore the enemies and rush through the building, there are 4 sniper rifles on the second floor. The more enemies you keep alive, the easier are the first couple headshots. Go down the stairs and use your Slo-Mo just for a short moment to aim on the head. A wave of soldiers will spawn outside. Just keep hiding in the building and leave your cover to activate Slo-Mo and perform a precise headshot. When you are not 100% sure don’t shoot.
Head Crab Removal
20 kills with a crowbar
You can only get a crowbar by possessing a cultist that has one equipped. Enter the Multiplayer Practice Mode and choose the Scenario ‘Black Gold’. It’s recommended to set the time limit per round down to 3. Playing on recruit will also help to make things easier. In round 2 the cultists will spawn (enemies that look like some sort of zombies). Alternatively, you can play through the story with Fettel to possess a crowbar cultist (e.g. interval 03).