Assume if the creator want to a make sequel, hey is my ideas

Map:Ancient Egypt
Based on the same version of the world from the second game

New plants:

Bonk choy
A melee plants that punch zombies
Cost:150 sun
Price:1000 point
Damage:Lower than peashooter but attack more constantly

Bloomerang
A ranged attack plant that has a projectile that hit multiple zombies twice
Cost:175 sun
Price:3000 point
Damage:Same as peashooter

Cabbage pult
A ranged plant that attack by lobbing cabbage. While it attack slower than any straight shooting plant, it deal more damage than them
Cost:100 sun
Price:1000 point
Damage:Twice as peashooter

Blockbuster
A melee plant that can destroy tombstone instantly in its lane(Doesn't matter how far is the tombstone)
(I will explain gravestone in detail later)
Cost:200 sun
Unlocked by doing an easter egg(Explain in detail later)
Damage:Same as bonk choy
I didn't choose grave buster due to insta use plant like potato mine and cherry bomb wouldn't work

Torchwood
If placed in front of a peashooter, double the damage of the peashooter. Attack by shooting spray of flame
Cost:125 sun
Price:5000 point
Damage:Higher than peashooter but lower than cabbage pult

New powerup:

Plant food
For the next 30 seconds, all plants are boosted
Example
Sunflower produce sun twice as fast
Attacking plant attack twice as fast and stronge
Torchwood pea boost multiple increase twice (2x to 4x)

Trap:

Wallnut bowling
For the next 30 seconds, wallnuts will roll into the lanes and when a wallnut hit a zombie it will bounce to a random lane. It can also kill zombies
Basic=1 wallnut
Cone head=2 wallnut
Bucket head=3 wallnut
Ra zombie(Explain in detail later) =1 wallnut
Pharoh zombie=(Explain in detail later)=4 wallnut
Tomb raiser zombie=(Explain in detail later)=2 wallnut
Gargantuar=5 wallnut
Imp=1 wallnut
Price:1000 point
Cooldown:30 seconds

Potato mine barrage
For the next 30 seconds, 3 potato mines will spawn in the lanes randomly for every 5 seconds and a single one can kill any single zombie instally except for gargantuar which require 2
Price:1000 point
Cooldown:30 seconds

Iceberg lettuce
Freeze all zombies and stop zombies from spawning for 10 seconds
Price:1000 point
Cooldown:30 seconds

New zombies:

Ra zombie
For every 5 seconds it will steal dropped sun. You can get back the sun by killing it. Once the first one spawned is killed it will drop the sun staff which is part of a buildable(Explain in detail later). Same durable and speed as basic zombie and spawn in round 5 and beyond

Pharoh zombie
More durable than bucket head and walk slower than basic zombie. Once the sarcophagus is destroyed, he will move faster(Faster than basic). When the first one spawned is killed it will drop a part of the pack a punch machine(Explain in detail later). Spawn in round 10 and beyond

Tomb raiser zombie
Same durable and speed as conehead. For every 5 seconds it will spawn a tombstone(Explain in detail later). Once the first one is killed it will drop a bone key for opening a locked door(Explain in detail later). Spawn in round 15 and beyond

Buildable:

Craft inside of penny

Pharoh sun collector
Parts
Sun staff: Kill the first ra zombie and collect it
Sun tomb: A room in the house
Place it in the basement of the house
Collect all sun without picking it up
(Replace solar panel)

Pack a punch machine
Parts: One from killing the first pharoh zombie and the other one by shooting it down off the roof
Place it in the backyard of the house
Pack a punch your weapon

How to turn on the power:

Turn on the switch which is located in the basement of the house (No need to collect parts)

How to unlock blockbuster: Kill the first tomb raiser zombie and collect the key to unlock a locked door in the house. Once unlocked there will be a safety box which you can get blockbuster by planting bonk choy near it which is going destroy it

Tombstone:

Tombstone are obstacles that spawn in round 5 and beyond at the lanes. It can block plant attack and your path.You can't plant anything in it. You can destroy it by shooting or with the plants. It can be instantly destroyed by infinite damage weapon (AAT, wunderwaffe, thunder gun and trap) and as mention earlier blockbuster. It has the same health as cone head. When destroyed it has the chance to spawn the following things:
Weapon
Powerup
Zombie

Sandstorm:

For every 6 turns, this special round occur. There will be zombies wrap into the lanes by sand tornado. A max ammo drop when all zombies are killed

Roster:

Plants:
Sunflower, twin sunflower, peashooter, snow pea, repeater, galting pea, torchwood, bonk choy, blockbuster, bloomerang, cabbage pult and flower pot

Zombies:
Basic, cone head, bucket head, gargantuar and imp in their Ancient Egypt counterpart, ra zombie, pharoh zombie and tomb raiser zombie

Boss fight:

How to activate: Reach round 25 and unlock all plants. After that speak to crazy dave and the boss fight begin. During the boss fight seed packet have zero cool down and cost 0 sun. Zombies also don't spawn

Boss:Zombot Sphinx-inator

Attack:

Wrap
Create and send zombies out in its mouth

Missile
Destroy a plant and create two tombstones(Doesn't hurt the player) . Can be stop by infinite damage (AAT, thunder gun, wunderwaffe and trap)

Stomping and dashing
Destroy any plants that is located near it's front two legs by tapping on the ground(Can down the player if hit multiple times enough) , then step back and charge forwards, destroying all plants and zombies in two rolls (Can down the player instantly even with juggernog).
The dash can be stop by inifinte damage (AAT, wunderwaffe, thundergun and trap) while the stomp can't be stop

Changing position
Leap into a random lane

It takes up a 2 by 2 area at the right side of the lawn

Have 3 stages

Infinite damage stun it instead of hurting it(AAT, wunderwaffe, thunder gun and trap)

Health:
Stage 1
A little above 2 gargantuars
Stage 2
A little above 8 gargantuars
Stage 3
A little above 6 gargantuars

90 percent damage resistance

The player and plants can't be in the 2 end of the right side of the lawn

Once defeated, end the game

That's all. How is my ideas for the possible sequel for this custom map
I can do pirate sea later