They Are Billions: Infected Swarm #15
Fifteenth and the last Infected Swarm mission in They Are Billions. Here, you have to face all types of enemies with the exception of Infected Giants - even the mutants will attack. It is important to build fortifications at the right location. This chapter contains a walkthrough and tips for this rather difficult mission.
How to unlock and goals
How to unlock: after completing the Highlands mission
Mission objective:
- Destroy all infected.
- Survive all the hordes.
The mission

- The last mission of the infected Swarm is not as difficult as it may seem - it is important, however, to complete all the previous ones before proceeding to it. Thanks to this you will have access to the largest possible number of Empire Points.
- Again, the defense works best when located around the main building. Set 2 rows of Wasp cannons, followed by 2-3 rows of Soldiers, and fill the rest of the space with Snipers. It is important to have about 100 Soldiers and 100 Snipers.
- Other Empire Points can be used for the manufacture of Trap Stakes or Wire Fence Trap. Enemies will attack from all sides, so it is necessary to block narrow passages with them.
- After the start of the mission, you will notice that the enemies will only come from the North. They will gradually appear from other sides.
- Set the Soldiers and Snipers as close to the cannons as possible. It is also necessary to establish a greater number of troops at the Northern part of the fortifications - a combined wave will approach from there, with twice as much enemies to eliminate.
- When the units begin to become veterans, the whole defense will be very simple - the enemies will not even be able to approach the fortifications.
- When the mutants appear on the battlefield, send a large group of Snipers to quickly get rid of them. Same in the case of large waves of fatties, Venoms or Harpies.
Tips

And now a few tips associated with the last mission of the Infected Swarm, namely:
- Instead of wasp turrets, you can use Lucifer units. Set 2-3 of them at each entrance with a group of Soldiers / Snipers behind them. Lucifer units and Soldiers will cope with most enemies, Snipers, in turn, eliminate special infected, Harpies, Venoms, and Mutants.
- Do not train Rangers - they deal too little damage, and their main advantages, that is, the speed of movement and a quiet attack is completely useless.
- Also, don't recruit Titans- they're very expensive, so you won't be able to deploy more than 1 of this type of unit per direction, and one Titan still won't stop the whole wave.
- They Are Billions Guide
- They Are Billions: Campaign walkthrough guide
- They Are Billions: The New Empire campaign
- They Are Billions: Story campaign - a few words of introduction to They Are Billions walkthrough
- They Are Billions: Mission 01 - The Hidden Valley
- They Are Billions: Mission 02 - The Last Bunker
- They Are Billions: Mission 03 - The hunter's Meadow
- They Are Billions: Mission 04 - The Crossroads
- They Are Billions: Mission 05 - Alpha Communications Center
- They Are Billions: Mission 06 - The Weapons Factory
- They Are Billions: Infected Swarm #1
- They Are Billions: Infected Swarm #2
- They Are Billions: Infected Swarm #3
- They Are Billions: Mission 07 - The Coast of Bones
- They Are Billions: Infected Swarm #4
- They Are Billions: Mission 08 - The Narrow Pass
- They Are Billions: Mission 09 - The Mines of the Raven
- They Are Billions: Mission 10 - The Lands of the Giant
- They Are Billions: Mission 11 - Cape Storm
- They Are Billions: Infected Swarm #5
- They Are Billions: Hydra Power Plant
- They Are Billions: Mission 12 - The Frozen Lake
- They Are Billions: The Foundry
- They Are Billions: Mission 13 - The Lowlands
- They Are Billions: Gamma Medical Center
- They Are Billions: The Nest of the Harpy
- They Are Billions: The Lonely Forest
- They Are Billions: The Oasis
- They Are Billions: Infected Swarm #6
- They Are Billions: Infected Swarm #7
- They Are Billions: Infected Swarm #8
- They Are Billions: Infected Swarm #9
- They Are Billions: The Prison
- They Are Billions: Steel Fortress
- They Are Billions: The Valley of Death
- They Are Billions: Omnicron Laboratory
- They Are Billions: The Noxious Swamp mission
- They Are Billions: Infected Swarm #10
- They Are Billions: Infected Swarm #11
- They Are Billions: The Villa of Terror mission
- They Are Billions: The Resistance
- They Are Billions: The Broken Land
- They Are Billions: The Forbidden Forest
- They Are Billions: Infected Swarm #12
- They Are Billions: The Wasteland of the Giants
- They Are Billions: The Phoenix Project
- They Are Billions: Infected Swarm #13
- They Are Billions: Infected Swarm #14
- They Are Billions: The Highlands
- They Are Billions: Infected Swarm #15
- They Are Billions: The Goddess of Destiny
- They Are Billions: El Dorado Mission
- They Are Billions: The New Empire campaign
- They Are Billions: Campaign walkthrough guide
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