Frost Dimension

The Frost Dimension is the 5th dimension in Plants vs. Zombies 3, taking place in an icy dimension which freezes your plants. The lawn is 5-by-9, as usual, but the ice coviring it may allow difficulties. However, you start off with the Heat-shroom, and they do appear on your lawn like Flower Pots on roof on the first few levels, so things shouldn't be too hard until they don't appear at the beginning of the level.

Effects on the game
The ice freezes your plants, unless using something such as the Heat-shroom, Torchwood, or Flaming Pea. Frozen Plants also don't freeze. For that reason, most of them are unlocked here. However, some Zombies like Snow Plow Zombies and Ice Skater Zombies can remove the ice, while Zombonis will replenish it.

New plants
Plants here such as the Heat-shroom, Torchwood, and Flaming Pea, are unlocked to heat up your plants, disabling freezing. Similarly, ice-based plants, such as Pine Freeze, Hockeweed, Snow Repeater, and Cherfreeze are given, being frozen variants of normal Plants. Aside from that is the Bamboo Shoot, Beet, Boxwood, Bananarang, and Pea Pod. 7 original plants, unseen before are unlocked, although this is the first 2D appearance of Bamboo Shoot, Beet, and Flaming Pea in 2D.

New Zombies
All Zombies here are resistant to the ice on the floor, making that be the difference between Frozen Zombies, Snow Cone Zombies, and Wooly Bucket Zombies from Basic Zombies, Conehead Zombies, and Buckethead Zombies. Eskimo Zombies though, are also immune to freezing, as well as the Zombonis. Zombie Bobsled Teams though, can be frozen, but not by the ice below. Snow Plow Zombies and Ice Skater Zombies will either destroy or wear away the ice. Ice Cream Zombies can't freeze from the ice below, although it is unknown why.

Trivia

 * All plants except Fire Plants appear in the final level, the reason they don't is because they will counter the ice plants.
 * However, Heat-shroom is in, because it's a necessity.