Modern Day - Day 1

Modern Day - Day 1 is the first level of Modern Day. After beating the level for the first time, the player will unlock Moonflower. Portals make their first appearance in this level.

Difficulty
The level itself is not too difficult, only consisting of the three zombie variants plus the Flag Zombies, and very few of them too. However, what makes this level escalate in that are the summoned zombies by one of the gimmicks of this world, portals. The zombies spawned appear in specific spots, which are generally in the player's defenses. The player should be aware of what portals spawn, where they spawn, and finally what zombies come out of it. Zombies like Mecha-Football Zombie, Robo-Cone Zombie, Pharaoh Zombie, Barrel Roller Zombie, and Shield Zombie can be devastating to the player.

Strategy 1
Recommended plants:
 * Plant some Primal Sunflowers on the back rows. When the first zombie comes, stall or stun it.
 * Start building some offense once you have enough Primal Sunflowers. Fill in three columns with Cacti.
 * When the Ancient Egypt portal comes, stall zombies coming out with Stallia or Stunion and Primal Wall-nut. This will prevent the Pharaoh Zombie from eating your plants easily.
 * Plant a Cacti next to the Pirate Seas portal to stop Barrel Roller Zombies from crushing your plants. Re-plant if needed.
 * Use the E.M.Peach after all robots come out of the Far Future portal. If needed, stall or stun the robots.
 * Give Plant Food to Cacti if a row is in danger. Use the Intensive Carrot if you cannot re-plant an eaten plant quickly.

Strategy 2

 * Created by 

Awesome Strategy of Nostalgic Awesomeness

Recommended plants:
 * Start placing Sunflowers, have at least two columns of them.
 * Potato Mine the first Zombie.
 * Now that you got sun, plant Repeaters, Peashooters and Snow Peas.
 * When the first portal comes, plant Chomper and dig it up to eat the zombies that come out.
 * When the Pirate Seas portal comes out, plant a Potato Mine to destroy the Barrel Roller.
 * Collect as much sun, use the Plant Food on Chomper when the Far Future portal comes out, but do it when all three mechs come out, so it can push them, place a Cherry Bomb next to the mechs.
 * Done.

Trivia

 * This level and Jurassic Marsh - Day 1 are the only 'Day 1' levels that have two flags.
 * It is currently the only regular level where Dr. Zomboss speaks, similarly, this is the first time he speaks during the first day of the world.