- Estimated achievement difficulty: 8/10
- Offline: 40 (720 )
- Online: 10 (280 )
- Approximate amount of time to 800 /1000 : 30h+/70h+
- Minimum number of playthroughs needed: 1 per Species
- Number of missable achievements: 6
- Do cheat codes disable achievements? No Cheats
- Does difficulty affect achievements? Yes
- Glitchy achievements: None
- Unobtainable achievements: None
- Extra equipment needed? None
Welcome to a great sequel in the Aliens vs Predator series. You can expect some good action, getting the full 1000 is going to be a piece of work.
Four of the missable achievements are the collectibles covered in the guide. However, there are two story-related achievements that are missable if you don't pay attention. The first is helping van Zandt via killing him before the Alien Larva bursts through his chest and the second is killing all Marines in the 2nd Alien Mission - Refinery. Take note of those two achievements in the guide and make sure you don't miss them.
Step 1: Playthrough on Hard
I recommend starting on Hard if you have some skill in first-person shooters. This way you'll learn how to play the three species and get to know the different levels. You need this knowledge to survive Nightmare difficulty since there are NO checkpoints. You should collect the Diaries/Jelly Containers/Trophy Belts as well as the second collectible for the Alien: Civilians who must be harvested. Check the achievement guide for details on all of these collectibles.
Step 2: Playthrough on Nightmare
This will be quite challenging. If you make a mistake you have to restart the entire mission. Manual saving doesn't work, so this depends solely on your skill. As Predator and Alien take it as slow and safe as possible. Nothing is more frustrating as the last Marine in a level killing you after spending thirty or forty minutes on the level. You basically play a level setup on Hard without checkpoints, so be careful as dieing can happen quite fast. For general information about each campaign please check the guide.
Step 3: Survivor and Ranked Multiplayer
Play survivor with some friends to get several weapon achievements and the survivor related killing achievement. All that is left afterward is playing ranked MP to get enough experience for the achievements.
Step 4: Mop up
If you are still missing some achievements, check the guide again how to unlock them.
It will take some time and skill to get through the campaigns on Nightmare and boosting the exp may be difficult. Good luck.