Credits to this site for providing the strategy for this achievement. I've only made a few changes and added some pictures to help identify the pop-ups you'll need to see.
It is highly recommended to attempt unlocking this achievement in casual difficulty. It is also possible to unlock it higher difficulties but you will have much more trouble with Z-Com and the slow rate of infection. In order to trigger the first event that leads to the final pop-up of this achievement, we must start the Necroa Virus in the USA and evolve an ability and transmission within the first 60 days.
Here's the recommended gene setup:
- Cytochrome Surge
- Aerocyte
- Spliced Activation
- Based Oxidisation
- Hydrophile
1.) Start in the USA. Evolve Saliva 1 and Drug Resistance as soon as you can. These two will cost 6 and 9 DNA, respectively.
2.) If you've successfully evolved the ability and transmission mentioned above within 60 days, this pop-up should appear:
 |
| DarkWater 'concerned' for missing geneticist |
3.) Gather up DNA and keep an eye on the news banner. There are times when these news fail to appear on the news headlines on the world screen, so be sure to manually check the news as well.
 |
| DarkWater denies containment breach in weapons facility |
 |
| DarkWater weapons facility shut down over security fears |
4.) After seeing both news headlines above, evolve the following:
- Insomnia
- Fever
- Photophobia
- Delirium
- Cytopathic Reanimation
Zombies should start appearing at this point. After a while a pop-up should appear:
 |
| [1.1] DarkWater created [plague name] |
5.) From this point on, you'll have to remember a few things to make sure you don't fail.
- Prevent the zombie population of the USA from exceeding 5 million. To prevent too much zombies from appearing, use the Zombie Horde ability by evolving Horde Pheromones and adding abilities that increase the zombie horde size. It's best to move zombies once the population reaches 4 million.
- If you get a pop-up saying "Authorities can't protect from the USA" this means that you'll have to start the game over. If that pop-up appears, DarkWater events won't show up anymore.
6.) There are a number of pop-ups that we'll need to wait for before we evolve anything. Remember the things I mentioned above.
The first pop-up that appears after [1.1] should be this one:
 |
| [1.2] DarkWater successfully analyses [plague name] |
Right after [1.2] this pop-up follows:
 |
| [1.3] DarkWater begin Z-REST experiment |
7.) After seeing the pop-up above, [1.3], evolve the following:
- Anaerobic Resuscitation
- Enhanced Motor Control
- Peptide Surge
- Acidic Reflux
- Naja Mortis
- Autothysis
Wait a few moments then the final pop-up should appear:
 |
| DarkWater's Z-REST device a failure |
This pop-up marks the successful unlocking of the Big Bang achievement. You can now choose to quit or finish the game.
Thanks for reading this guide and HSG!
