M is for Metal is the fifth level of Vasebreaker in Plants vs. Zombies, Plants vs. Zombies: Journey to the West, and Plants vs. Zombies: Great Wall Edition. It includes several zombies with magnetic gear and equipment and some Magnet-shrooms to take away such gear equipment.
The level's name is a reference to the mnemonic "[letter] is for [word that starts with the same letter]." It says metal because most of the zombies have metallic objects on themselves that should be stolen by a Magnet-shroom.
- As with all the Vasebreaker levels, try to break the vases on the right side of the lawn first. The most dangerous zombies in this level are the Football Zombie and the Jack-in-the-Box Zombie (both of which have a weakness to Magnet-shroom, emphasizing its importance).
- Plant Magnet-shrooms in the front of the lawn and protect them with Pumpkins as soon as possible when you get them.
- Plant left-facing Repeaters and Snow Peas on lanes with exposed Buckethead Zombies or Football Zombies, and plant Squash near any zombies who come too close or are in a lane clear of plants.
- Place Hypno-shrooms on the left side, in case a Football Zombie gets away. There is no time limit, and you can let out the zombies whenever you choose to. Therefore, a viable, but slow strategy is to wait until Magnet-shrooms recharge before breaking certain vases.
- In this level, it may be possible for Jack-in-the-Box Zombie to get into the house without his Jack-in-the-Box if there is a Magnet-shroom next to it, as he will steal his Jack-in-the-Box, allowing him to walk freely.
- This is also the only Vasebreaker level where the player can avoid having his Jack-in-the-Box explode, although it is possible to kill him with a perfectly timed Squash or other instant-kill plants.