Start on Casual Difficulty.

Genetic Code:
ATP Boost
(Darwinist)
(Teracyte)
(Xerophile)
Sympto-Stasis
Only ATP Boost and Sympto-Stasis are required.

Starting location: China

The main idea is to quickly infect wealthy countries with gift planes in the midgame, since people overwhelmed with happyness won't work on the cure.

Using the DNA points given by ATP Boost, evolve:
Santa's Little Neurax Worm, Festive Tendrils, Emotive Radar.

Then evolve:
Radio Worm and Memory Lane

Digital Elf and the following two symptoms ---- Digital Herald and Digital Angel
(we may call these three symptoms Digital Elf +2 in short)

Laughter +2
We want to increase severity (happyness in this scenario) before we spread.
The more severe you are, the more DNA points you get spreading to a new country!
This is a basic fact in all situations.

Surprise Delivery*4
Make sure you evolve them one by one, after poping red bubbles given by the previous one.

Stocking Filler +1

Finally, evolve Gift Plane, which brings us into the middle game.

This is the most intense part in the game.

Deliver your first 'gift' to Japan, second 'gift' to Australia while evolving Present Parachute +2.

Whenever you recieve a gift plane, press E to look at Cure developing information:
UPDATE: Sorry that I've deleted my screenshot, totally unaware that it would affect my guide.

And then give the 'gift' to the most active one:
UPDATE: Sorry that I've deleted my screenshot, totally unaware that it would affect my guide.



Evolve:
Snowball

Genetic Hardening +1

Solar Perfume and Glow Worms
We already have Snowball, Gold Digger and Memory Lane to deal with cold/wealthy countries
Let's put emphasis on Africa and South America

Contentedness +2

Solar Perfume 2 and Wild Side

Friendship +2

Indulgence +2

Enjoy!

You can wait and see how you dominated the world with happiness, or might as well evolve Genetic Reshuffle for a higher score.


I've tested a few games by exactly following every instruction in the guide, and got scores no less than 95000. So I'm pretty confident that you will get 3 biohazards on your first attempt.

If there are any problems, feel free to ask and I'll be happy to help.
Good Luck!