The world is your oyster. You can make all sorts of mods with any story and atmosphere.
It sounds like you may be interested in potentially making a mod (or you are just interested in someone else making one, in which case the following resources should be helpful to such a person). You will probably need to learn C#, PowerShell, shell, etc. and work with this SDK:
To prove my point that you can make a mod with your own story and atmosphere, this mod is a (literal) bug swarm strategy game: OpenSA
For the mod itself, you will be mostly programming in C# and sometimes another language if you decide to use one (it seems with this particular engine, modders tend to either use just C# or C# and Lua). Shell, make, and other languages are typically used for the packaging and installation/generation/compilation/etc. scripts/tools of the mod.
The world is your oyster. You can make all sorts of mods with any story and atmosphere.
It sounds like you may be interested in potentially making a mod (or you are just interested in someone else making one, in which case the following resources should be helpful to such a person). You will probably need to learn C#, PowerShell, shell, etc. and work with this SDK:
https://github.com/OpenRA/OpenRAModSDK
You can look at community mods here to find examples to learn from and see what is possible:
https://www.moddb.com/games/openra/mods
You can click on one of the mods and potentially find their own git repository, such as this one: OpenE2140
This mod used Lua as well: Generals Alpha
To prove my point that you can make a mod with your own story and atmosphere, this mod is a (literal) bug swarm strategy game: OpenSA
For the mod itself, you will be mostly programming in C# and sometimes another language if you decide to use one (it seems with this particular engine, modders tend to either use just C# or C# and Lua). Shell, make, and other languages are typically used for the packaging and installation/generation/compilation/etc. scripts/tools of the mod.