Welcome to this guide dedicated to unlocking the most difficult achievements of They Are Billions. As I was starting to do some achievement hunting and figuring strategies to unlocking them, I figured I would lay them down in written form to help my fellow gamers unlocking them as well.

I will mostly focus on Survival related achievements that require actual strategy and not simply investing ungodly amount of time playing the game (looking at you Killing X Zombies achivements).

As of the time writing this guide, I haven't actually unlocked all the achievements that will be talked about in this guide. Nonetheless I will talk about the potential strategies that will be needed to succeed. Some of those achievements actually don't interest me at all and I will probably never unlock them for various reasons that will be explained in each section.

This guide does require a decent knowledge of the game and the ability to beat the game consistently at 100% factor difficulty.

Without further ado let's begin.

What are the settings that I used for most of these achievements?

Simply play on the Deep Forest map with 100 or 120 days adjusting the zombie population to go above 100% factor difficulty.

The choice is actually motivated by simple factors:

First, the Deep Forest map is a very easy map as it provides many chokepoints, a lot of food and NO SPECIAL INFECTED. Yes you heard it right; it means no giants, no mutants, harpies, venoms or even chubbies on the map. You may still encounter harpies and venoms but only on the last wave and chubbies after the 3rd or 4th wave depending on your settings. It makes the game so much more forgiving in terms of micro.

Now 100 or 120 days depends on your confidence, level of macro and your sanity. 120 days make for super long games and I no longer have the patience to go through all that slog (especially the late game where it ends being a waiting game where you know you have won). If you feel confident you have enough macro skills to pull off a successful economy despite the constraints in less than 120 days then by all means go for it. 120 days will make it easier though.

Finally, the Zombie population doesn't change much as there's no special infected. Regular zombies are very easy to deal with.

The first achievement we are going to tackle is the Soldier Wrath achievement. You need to win a 100% factor using soldiers only. This is in my opinion one of the easiest challenge as soldiers are extremely strong with the settings that I suggest.

The strategy:

It's a simple regular game but you need to avoid a few things:
Do not recruit anything else than soldiers.
Do not build any Attack Towers (Ballistas, Executors, etc.)
Walls and Garrisonable towers can be built.
Do not use the Inn to recruit anything but soldiers (to be verified).

You can however use the Mayor's bonuses to your heart content and the units you start with.

You just need to recruit soldiers and use them to push. Before Wave 1 make sure to have 5-6 Veterans to help deal with the first wave and then dispatch them to patrol the side of your colonies. veteran soldiers can easily deal with a dozen of runners at the same time, especially if you kite.

The second achievement we are going to tackle is the Ranger Revenge achievement. You need to win a 100% factor using Rangers only. This is a difficult challenge but not an impossible one providing you prepare carefully.

The strategy:

It's a simple regular game but you need to avoid a few things:
Do not recruit anything else than rangers.
Do not build any Attack Towers (Ballistas, Executors, etc.)
Walls and Garrisonable towers can be built.
Do not use the Inn to recruit anything but rangers (to be verified).
Use traps (to be verified)

You can however use the Mayor's bonuses to your heart content and the units you start with.

This challenge is the easiest at the beginning but becomes very difficult in the late game.
Push and build a lot of rangers to expand your colony, finding chokepoints and ressources. Make sure to have around 10 rangers for the first wave (or having unlocked traps). Put 9 rangers in a ball and use 1 to kite the horde in a circle. Zombies are very easy to kite with rangers and this is a skill needed if you want to succeed on this achievement.
I haven't tried it yet but I believe the last wave would require a lot of traps (I don't think they count as attack towers) and not expanding as much (leaving space for traps).

I would suggest reloading if you don't get the first mayor that boosts your rangers (+1 Range and Vision Range) but I do think it's possible to succeed without it.

The third achievement we are going to tackle is the Sniper Slaughter achievement. You need to win a 100% factor using snipers only.

The strategy:

It's a simple regular game but you need to avoid a few things:
Do not recruit anything else than snipers.
Do not build any Attack Towers (Ballistas, Executors, etc.)
Walls and Garrisonable towers can be built.
Do not use the Inn to recruit anything but snipers (to be verified).

You can however use the Mayor's bonuses to your heart content and the units you start with.

Some people believe that Snipers are the best units in the game. They would be correct as they help deal with special infected with ease. However when there's no special infected soldiers are much more powerful. This achievement is therefore a bit harder than soldiers. They are also more expensive and will make it harder to push in the early game without the use of soldiers or rangers You actually need a couple of days of saving money before starting to push as you need to build a Wood Workshop and unlocking the Sniper tech (700 gold and a long time to research).
Once you get the ball rolling it's very easy as a dozen snipers will wipe all the zombies on the map without the need for micro. Be careful though as a lone sniper is vulnerable to being overwhelmed and cannot run away as easily as other units due it's slow speed. In the end just park your snipers in towers on chokepoints and enjoy.

As an extra challenge I'm actually trying to unlock this achievement the No Wall achievement at the same time. Not sure if I'll succeed on doing both at the same time but the Sniper Slaughter achievement is definitely on the easy side as far as achievements go.

The fourth achievement we are going to tackle is the No Towers needed achievement. You need to win a 200% factor without using attack towers.

You will need to adjust the settings a bit in order to reach the 200% factor. Simply reduce the number of days before the end game should solve it easily.

The strategy:

It's a simple regular game but you need to avoid a few things:

Do not build any Attack Towers (Ballistas, Executors, etc.)
Walls and Garrisonable towers can be built.


You can however use the Mayor's bonuses to your heart content.

I'm actually mad I didn't complete this one at the same time as the soldier one. Now that I have completed the game while using only soldiers I would suggest doing the same strategy here. If you have trouble then complete your defenses with snipers to help deal with Chubbies during later waves.

The fifth achievement we are going to tackle is the Peaceful achievement. You need to win a 100% factor without recruiting units.

The strategy:

It's a simple regular game but you need to avoid a few things:
Do not recruit anything.
Walls and Garrisonable towers can be built.
Do not use the Inn to recruit anything (to be verified).

You can however use the Mayor's bonuses to your heart content and the units you start with.

This is the achievement that makes me think that recruiting at the inn can lock you out of achievements. I actually did this one while using the Inn and it wasn't difficult. Without the Inn i don't think it will be harder as I had cleared the map by day 45 or so. Without the Inn you will simply need more time to clear.

This achievement will need you to abuse how noise works in the game. Simply build 2 Ballistas at every chokepoints leaving room for a Shocking Tower in the middle. 2 Ballistas will make sure you aggro zombies while ensuring your chances of not being overwhelmed. Shocking Tower make waves super easy without special infected (they will die on the last wave because of spitters though). Build out your economy like any other games focusing on having one ballista for the first wave and unlocking executors in the late game.

The sixth achievement we are going to tackle is the Open Mind achievement. You need to win a 100% factor without walls. This is a hard challenge as walls make your life so much easier.

The strategy:

You need to avoid a few things:

Walls and Garrisonable towers can't be built.
Otherwise anything goes.

You can however use the Mayor's bonuses to your heart content.

I would recommend doing the same strat as the Soldier Wrath achievement but you can use the small turrets as wall and executors to block out chokepoints.

The seventh achievement we are going to tackle is the Best General achievement. You need to win a 100% factor without losing a single troop.

The strategy:

It's a simple regular game but you need to avoid a few things:
If any of your troops die, it's game over.
You can lose buildings and repair them.

Soldier strat it is. That's how I unlocked it without trying. They are robust and will survive even if you are not careful. The main reason you may lose troops in a game of TABS is either because of a giant or special infecteds (notably venoms). The only venoms will be during the last wave when your soldiers are in towers. Babysit them and check if your towers are about to fall (in which case retreat the soldiers inside). Otherwise it's simply a matter of pausing the game and retreating every time you get a Unit is being attacked alert.

This achievement requires winning a 100% Factor Game without pausing the game.

The strategy:

I do not recommend trying to do this achievement at the same time of others but it can be done. If you wish to attempt so, I would recommend trying with the Soldier's Wrath achievement as it's one of the easiest and one requiring less micro compared to other achievements.
Just play normally without pausing once (I believe you can still press Esc to Save and Exit the game if needed or if you need a break). I would suggest deactivating the pause hotkey to make sure you don't press it inadvertently.