They Are Billions: Critique of the Horde

They Are Billions is a Real Time Strategy game produced by Numantian Games and released in 2019. Combining the RTS genre with zombie horror flavored with steampunk. This was a game that was technically impressive at the time for the number of entities; namely zombies, that it managed to pack In all At once. They Are Billions was sent out into the world as early access in 2017 and received multiple accolades and solid critical scores through to its release, which included a full campaign mode to flesh out the Standalone maps and player generated maps. That being said, the game had a sharp difficulty curve, underpinned by several mechanical shortcomings and a campaign that failed to generate a strong or memorable narrative.

There are practically no true characters to speak of outside of the campaign, mayors are named, but have no characterization beyond that. In the campaign, the player can take on one of two generals, which is little more than a sprite re-skin. The only character with even the slightest development is the emperor of the surviving human colonies; Crane Quintus, who is the de facto emperor of the last remaining stronghold of the living the Imperial City. In the future where mega cities have spread and the population ballooned into the tens of billions, an infection, and the subsequent attempts to cure it created a unending horde of zombies that destroyed the old world. The majority of the story is told to the player through old signs and newspaper articles that fill in as backstory.

The open ended nature of both the campaign and the rest of the game don't really lend itself well to an in-depth storytelling, to the detriment of the game overall.

The campaign also handles a number of staple mechanics of RTS’ in unusual ways that while giving players a great deal of agency, didn’t really land particularly well overall. For example, there is a tech tree and player have some liberty to decide which levels to take on and in which order. However is doesn't always lead itself to the most succinct difficulty curve, especially since the game's natural difficulty settings are quite unforgiving.

Mechanically much of the game would be familiar to returning players of the RTS genre, unit controls, building, user interface, and base design. With various other staples of the RTS genre being absent, especially in the campaign. Where you'd expect to see more scripted events and in level storytelling, it's pretty bare bones.

The campaign adds more variety to level. In addition to the skirmish style levels available from the Early Access there were more pure tower defense levels as well as tactical missions where the player controls their General in gameplay more akin to Bauldur’s Gate II and Classic Fallout with different emphasis on strategy and exploration.

Gameplay was solid and stable not just in the developer created content but also the modded and user generated maps. This stability speaks volumes to the quality of the games backend, where mods are still performant at scale. Kiting was an ever present issue. Kiting the simplistic enemy AI is something that the game almost requires on higher difficulties, but it is an extremely frustrating manual process.

A nice feature that really shows that this is still actually ongoing, is on the main loading screen, there is a counter for the global number of zombies killed across the entire player base, and it is in the trillions as of this article.

Gameplay didn’t have a strong draw. I found the high difficulty and long duration offsetting all the positives. However, with all the things that I mentioned beforehand, the game definitely could have accomplished a lot more in both its campaign and with more diversity in its levels.

They Are Billions sound design was solid for the most part, one foible where selecting and building units would trigger dialog. There are very few of them, and you will be hearing them a lot whether you want to or not.

Music has this great bombastic orchestral quality to their soundtrack. It only has a few tracks but the blend of mechanical and instrumentals. They aren’t exactly marches, but it's very distinctive and fits well with the steampunk themes, which I thought was nice.

Art design was quite good as well. The game relied mostly on 2D sprites for just about everything. You can see there's a good amount of quality particle effects, just a good overall design for an RTS. I even like the UI with lots of nice little steampunk flourishes, and it's packed with lots of little quality of life things that you don't usually see even in some of the more established RTS genres, tool tips and the ability to select all units of particular types was something I found impressive.

I've already gone over the game's other modes. There are no DLC or Expansions to speak of, and at this moment, there's no evidence that any kind of sequel will be developed, even though I think there's a good solid demand for it.

They Are Billions achievements reflect the game's overall difficulty, with some of the achievements being quite brutal. There are achievements for getting through the entire game without pausing, only building certain types of units, but the truly diabolical one is Infected Killer Level 10 which involves having to destroy 100 million infected zombies.

As for prospective improvements I might necessarily recommend, I know, maybe to a sequel. Definitely the campaign needs a more structured story and a lot more scripting in their level design comparable to other RTS. While most of the levels have slight modifiers to keep them feeling fresh they don’t leverage all the features already in the game to full effect. Levels aren’t tied together thematically, narratively, or structurally so there definite room for improvements. For example none of the levels have pre-built sections so every level is essentially a start from scratch.

There are no formations for allied units. There's very little nuance to gameplay level diversity is also quite low if you're sticking with the vanilla maps provided by the campaign and the game itself,

No secondary goals or objectives beyond protect the command center. Zombie spawn holes; present in tactical missions, could have been a game changing feature in regular maps. The tech tree was something that could have been handled better. The tree doesn’t carry many benefits if you don’t lock yourself into a single irrevocable play style.

In my analysis let’s look at the methods the game implements to optimize the games entities. They Are Billions, has a huge number of zombies on screen at a given time, and while they can impact performance once the numbers really get up there. It performs well above what you'd expect. Numantian Games uses a bunch of clever techniques to keep performance high despite these number of entities.

There are a few givens; all the zombies are sprite based with makes them fast and light weight in terms of resource usage. The small number of sprites in the game overall and the limited animations means it has lean sprite atlases that don’t require many system resources in order to keep everything in RAM. The developers did a few extra things to their unit entities animations to tune performance. Idling zombies have slower animations meaning they don’t need to be update as often. When units die, they are immediately transitioned to even lighter weight versions of the instance which is something I've actually looked into before with GameMaker Studio (Dynamic to static drawing).

Many of the buildings are decorated using light weight shaders along side or instead of being animated. This has the complementary effect since it makes buildings look dynamic at cost. Pooling is used to great effect in this case combining classic techniques like batching the common entity logic with GPU based batch meshes that leverage the ECS style implementation of the engine for higher entity counts.

The most impressive is the way they handle pathing. For the most part, it relies on three sets of systems to determine if the zombie has a path or not.

1. They will idle: requiring no pathing whatsoever.


2. When they spawn as part of a wave they’ll swarm using a single virtual guide rather than multiple individual paths.


3. When zombies are attacked (active or using the games “noise” systems) they’ll snap out of either of the other pathing states and pursue.