Another concept :)
In The Past, there are graves, and it takes place in a graveyard, and it has a day & night cycle. A scientist (Zomboss, before he became a zombie) necromanced some zombies, thats how Plants vs. Zombies started, apparently.
Graves will spawn on the lawn, after the last wave, they spawn zombies (Random), if you don't destroy them in time.
Levels: Part 1: 12, Part 2: 13
Long-ranged shooters that hide when zombies get near them. (when hiding, cannot be eaten) Unlocked on TP - Day 1
Plant Food: Shoots 60 spores, and shines a bright light on all zombies on the lane, stunning them.
Collects uncollectable armor that Magnet-shroom can't, collects coins and gems for you. Unlocked on TP - Day 24
Plant Food: Unleashes a powerful gold magnetic force that attracts all gems, coins and uncollectable armor that Magnet-shroom can't then throws them at zombies in every lane (randomly).
Shoots stalks in a 3x9 area. (cannot shoot backwards) Unlocked on TP - Day 6
Plant Food: Rapidly shoots 60 stalks in every direction.
Beet (costume: Beetboxer)
Headbutts zombies into submission. (Different from Bonk Choy, since it can hit multiple zombies, but Bonk Choy hits one zombie at a time)
Plant Food: Headbutts all zombies in a 3x3 area.
Heals all surrounding plants, regains their health. Unlocked: TP - Day 13
Plant Food: Will make all plants surrounding it temporarily invulnerable.
All zombies from tutorial, reappear, except Flag Zombie.
Scientistic Flag Zombie
Marks the arrival of a huge necromanced "wave" of zombies. Encountered: TP - Day 1
Toughness: Protected (wears a helmet to be stronger)
A shocking Gargantuar that has twice the health of a normal Gargantuar. Encountered: TP - Day 25, Endless Zones.
Toughness: Ultimately Great
Damage (electric pole, chains to other plants): Light
Teleports onto a random square on the lawn, needs to recharge after. (Gold Magnet can pick up teleporter) Encountered: TP - Day 12
Zombotanies. Encountered: Zombotany Minigame (button just like Vasebreaker, takes place on random worlds)
All zombotanies, except Gatling Pea, plus Puff-shroom Imp, Chomper Zombie, Pea Pod Gargantuar, and Fume-shroom Imp.
Makes the big plays. Encountered: TP - Day 9
Toughness: Very High
Makes the extreme plays. Encountered: TP - Day 8, along with normal Gargantuar
This zombie carries an explosive surprise. Encountered: TP - Day 9
Summons 10 random graves, and already spawned graves will summon Basic Zombies
Save our Seeds: Day 19
Last Stand: Day 11, Day 16
New Brain Buster: Whack a Zombie
Day 9, Day 24
Zombot Nostalgia Bot, After beaten, new achievement achieved: Into the Present
Rules them all.
Special: Crushes plants in front of it, uses camper attack, throws potions to boost zombies.
Damage: Breathes fireballs and iceballs to crush a whole lane of plants.
It will summon zombies:
Phase 1: Basic Zombie, Conehead Zombie, Football Zombie
Phase 2: Football Zombie, Basic Zombie, Buckethead Zombie, Scientist Zombie, Any Zombotany
Phase 3: Giga-gargantuar, Giga-Football Zombie, Buckethead Zombie, Scientist Zombie, Any Zombotany
Back to the Past
Every 100th level, you get to fight Zomboss, in a last stand setup.