Here is the full list of all 22 Zombie Within achievements.
Win a game in less than 5 minutes.
Win a game in a procedurally generated map.
Win a game against a team of Bots.
Win a game without using any upgrades.
Break 8 generators in one game.
Kill 6 civilians during one zombie transformation.
Win a game without transforming into a zombie.
Have all generators broken at the same time.
Fix 8 generators in one game.
Win a game without killing any civilians.
Detect 5 imposters in one game using the Scan ability.
Detect 5 imposters in one game using the Trap ability.
Find 8 infected areas in one game.
Win a game without using any abilities.
Break 100 generators.
Fix 100 generators.
Play 100 games as Imposter.
Play 100 games as Defender.
Win 100 games as Imposter.
Win 100 games as Defender.
Kill 100 civilians.
Kill 100 Imposters.