-Estimated achievement difficulty: 3/10
-Offline: 12 (200)
-Approximate amount of time to 200: 5-10 hours
-Minimum number of playthroughs needed: 1
-Number of missable achievements: 0
-Do cheat codes disable achievements? No cheats
-Does difficulty affect achievements? No difficulty
-Glitchy achievements?? None
Step 1: Story Mode
By simply playing through the game you will get some story related achievements Back with the X, Big Brain Brian, Thought this was a Zombie Game?, and Touch Base. As you make your way through the game. Recommend you do A Legion of Zombies, Fists of Fury & Can’t touch this as early in the game as possible. This will save you a lot of hassle and make the rest of the game hassle free. Also keep an eye out for 'Dev Cards' as you play through the game. You can follow the 'Dev Card Hunt!' Location Guide to help you locate them.
Step 2: Clean Up/Dev Card Hunt!
You should all the achievements by now for the exception of The Collector & Getting to know each other. After the game is completed, you can select Resume Game from the Main Menu to keep playing. You can also do any other achievement you missed the first time around. Just keep in mind that when you resume the game the zombies will be tougher, since every zombie type is unlocked at this point.