Toys vs. Nightmares
While it may have mechanics similar to P vs Z the game itself has a few original ideas and also has plenty of room to expand upon.
Great game over all I can tell you put a lot of effort into and it shows. I like how the idea came to you and you created the game from an actual event in your life. Good presentation as well as awesome UI and very intuitive gameplay. The game has a fun factor and has a lot of replayability.
This concept sounds like part 2 of Plants vs Zombies.
I give you a 9.