Plants vs. Zombies: Battle for Neighborville

Just load up a graveyard ops and spawn bots like you would potted plants. There's about 8 or so places to do this on each map. Just pick the first bot and it should get taken out fairly quickly so you can spawn another one on the next round.

This achievement, as well as its Good To Grow counterpart, is surprisingly easy in the story mode of this game. Either go to "Pressure Pier in Town Center" by talking to Dr. Nurse Doctor, or "Weirding Woods" by talking to Seabasstian. You may need to play through the main story for a bit, but once you have freedom to explore you want to find "Monkey".

In "Pressure Pier In Town Center", Monkey can be found in Pressure Pier.
In "Weirding Woods", Monkey can be found in the Z-Tech Factory.

Once you have found him, you'll want to interact with the glowing Grave-O-Matic next to him. When you hover over it, it should say " Play Ops". From here, just play a few rounds of Ops, making sure to fill the bot stations every time they are killed.
The default Rocket Bots have no cooldown, so you can spam these around the map to maximise time.