Estimated Trophy Difficulty: Pending (3 or 4 in my opinion)
Offline: 12 (0 1 4 7)
Approximate Amount of time to 100%: 5-10 Hours
Minimum Number of Playthroughs Needed: 1
Number of Missable Trophies: 0
Glitched Trophies: None
Do Cheat Codes Disable Trophies?: No Known Cheats
Does Difficulty affect trophies?: No Difficulties
Step 1: Play through the game: While you play make sure you get the Can't Touch This trophy as early as possible, along with A Legion of Zombies to avoid frustration later. You can collect Dev Cards along the way or you can wait until Step 3. The same goes for Character quests. Within the first minute or two of the you will earn Kill a Zombie.
Step 2: Beat the game: Simple enough but if you have trouble beating it you are given the option to lower the difficulty if you die multiple times in the same levels. Be sure to get other trophies here like Watch This!, Master Craftsman, and Fists of Fury. This is where you will earn Back With the X, Big Brain Brian, Thought This Was a Zombie Game? and Touch Base which are all story related.
Step 3: Mop up: At this point you should have a majority of the trophies but if you missed a few earlier don't worry, once you have beaten the game, you can select Resume Game from the Main Menu to keep playing. If you are missing a couple of Dev Cards or Character quests, now is the time to finish them up so that you earn The Collector and Getting to Know Each Other. You can also complete any other trophies you missed. Be aware that some trophies will be harder than before since every enemy type is unlocked at this point.
[PS3T Would Like to Thank Zayne for this Roadmap]