- Estimated achievement difficulty: 2/10 [Achievement Difficulty Rating]
- Offline: 10 
- Online: 0
- Approximate amount of time to 1000: <1 Hour [Estimated Time to 100%]
- Minimum number of playthroughs needed: 1 level in Campaign Mode and 1 level in Onslaught Mode
- Missable achievements: None
- Does difficulty affect achievements: Yes, must play a Campaign level on Nightmare for The Nightmare Rages (150G)
- Unobtainable/glitched achievements: None
The infection goes nation-wide in Outbreak: Epidemic, an action-focused co-op survival horror adventure. Featuring the great Outbreak series gameplay with greater mobility, crushing difficulty and more camera options than ever before. Alone or in 2-player local co-op, fight through the Campaign story mode, the wave-based Onslaught Mode and all new Experiments Mode scenarios. Choose your survivor, class and level up to unlock new buffs for your survivor as you face the nightmare. You'll need to manage your inventory and supplies carefully, so make every bullet count!
The game's achievements can all be picked up extremely quickly and require only completing the Tutorial chapter of Campaign and one playthrough of a single scenario of Onslaught mode.
Your first step will be to play the Tutorial chapter on nightmare difficulty, netting you all the campaign achievements as difficulties stack. See The Nightmare Rages (150G) for more information.
Thereafter, a playthrough of Onslaught mode should net you all remaining achievements. See Take Down the Horde (100G) for how to easily complete this.
Finally the only achievement you may not have gotten upon clearing the two modes is Overwhelming Infection (50G) for dying, simply start a new game then stand next to the first zombie you find.
Whilst the game tries to replicate the survival horror of titles of old, the achievements can be gained quickly without really playing through it.