At the first, zombies appear at random timing at random lines is mostly a kind of preparation.

One or two zombies come together at different lanes at random to invade which gives a bit of time for the defender to prepare his defenses.

The tutorial given by the tower is also a kind of similar.

From the start, the zombies appeared randomly giving plenty of time to atleast to plant different kinds of plants in different lanes.

Plants vs Zombies is a very simple tower defense type of game.

The winning method is very simple. It requires to collect as much sun, and plant the most suitable plant at the most suitable time.

As long someone has a bit of wisdom and gaming experience can easily win.

By the time, zombies came one by one, I already made a proper defense.

Five Sunflowers.

Five Peashooters.

Three Wallnuts.

And two Potato Mines at the no-Wallnut lanes which are yet to spurt out of the ground.

A pretty simple structure. 

And with that I also collected plenty of sun points.

Sun Points - 250

Wallnut and Potato Mine are still in recharge state, since unlike Sunflower and Peashooter the recharge rate of both is quite slow.

Most people might wonder why create a proper defense system?

The reason is quite simple. It's because of the big move - Waves.

"Oh, talk of the devil!"

Unlike before, just in opposite of the plot were not one or two zombies, but an army of zombies!

And in the front was a zombie with a conehead grabbing a red flag with a brain depicted on it.

The flag was very indication of a zombie wave. But...

"Normally a normal zombies carry a flag but why a conehead zombie is holding it?"

Flag Zombies, the zombies who hold the zombie flag. Normally, they are just normal zombies with not much speciality but here the conehead zombie seems to holding it.

"It is indeed weird, but I guess it doesn't matter much."

The flag doesn't have some kind of power, so it the end it doesn't matter who holds it.

Rather than that, the problem is that the zombies are too much for a mere tutorial.

"Aren't the zombies are too much?"

I counted up them and probably there are more than fifteen zombies including five or six conehead zombies.

Before I could even think and derive a proper strategy, the zombies marched towards the house raising the flag.

And the voice like before announced the invasion all around the house.

"Zombie Wave Incoming!"

Pop! Pop!

Peashooters started to do their work. All of them started to shoot at their respective lanes to kill the zombies.

Unlike before, in the waves zombies invade from all the lanes at once. So, to win the defender has to protect the house using all the lanes simultaneously.

"Even though the wave is a bit bigger than I expected, I don't think there will be a problem."

Conehead Zombie who was embarking on the middle lane with his group of zombies continued to walk ahead sustaining damage from the peas.

This zombie acted as a shield and protected the normal zombies and it itself didn't get much damage because of it's enriched defense.

The conehead zombie has higher defense than normal zombies. While normal zombies need 10 peas to get killed, conehead zombies needs 20 peas.

By the time of 30 seconds, the zombie would easily reach near the Peashooter.

But...

Ka-pow!!

Fortunately, I have an insurance. The conehead zombie and his companion zombie together stepped on the Potato Mine and got ka-pow-ed.

And like that, another pair of zombies died because of the mine in another lane.

Unfortunately, there was no conehead zombie among them.

Both lanes with mines exploded and killed four zombies leaving eleven zombies.

The top lane has four zombies with a conehead zombie whose cone has already fallen due the pea attacks.

"The wallnut for now is somehow blocking them, but I am not sure how long it would take... Oh! Speak of the devil!"

The wallnut collapsed making the road open to invade. But I already have sufficient sun points with no need of recharge.

I quickly took out a wallnut and quickly placed it just in front of the group of the three zombies.

The conehead leader was already down after 20 hits, and all I have to do is to defend my plants from these three.

With a new wallnut, the first lane is complete. I think one Peashooter will do it's work.

Th sunflower continued to generate sun, and I collected them as fast I could. 

The third lane and the fourth lane are also kind of clear. The potato mine did it's work and only one zombie was left in each lane.

For a single Peashooter, it's quite easy even if the zombie is just two patches away.

The problem is the fifth lane which in under attack from three zombies with two being conehead zombies.

The wallnut is already in the verge of falling down, and because of two conehead there isn't much insignificant damage.

"I should switch plants."

With not much thought, I quickly removed the sunflower of the fifth lane and planted a Peashooter in place of it.

And with that I used the refreshed Wallnut to replant in the same patch of the old wallnut.

"This is also clear."

With two Peashooter behind a wallnut, I believe it will take care of these three zombies.

I turned my head to look at the second lane which had two conehead zombies. 

"Wha?"

I couldn't believe my eyes. The wallnut is half eaten, and it wouldn't take much time for it to fall.

The Peashooter is shooting and the first conehead zombie is also verge on dying. But...

"Even if the first zombie falls, it already has cleared the wallnut for the zombie behind it!"

And as I said it, the wallnut disappeared and the zombie's head fell down simultaneously.

But the conehead zombie behind it is in full throttle. It already didn't get any damage due to the first conehead zombie, and now it is quite near the Peashooter.

"What should I do? It's already near the Peashooter! Wallnut? No, it hasn't refreshed yet! What to do?"