Plants vs. Zombies: Battle for Neighborville
50 Achievements
EA Play
One BIG Step for Zombies
Earn 200 vanquishes as a Space Cadet
How to unlock the One BIG Step for Zombies achievement in Plants vs. Zombies: Battle for Neighborville - Definitive Guide
Pretty easy achievement. This can be earnt quickly by simply camping at the opposing team's side in Giddy Park and grinding the bots that appear there. Just keep on vanquishing them for about 10 minutes and the achievement should unlock.