How to build?

[Napoleon-BlownApart]

Thanks for this interesting project.
I installed the app from the app store, but there are some small problems in it. For example, some of my ships are not showing in the Assets list.
Whilst trying to figure out where to post a question about the missing data, I came across this repo (as well as the supporting repos). This prompted me to clone and attempt to build the app locally. However, there are no build instructions and some dependencies which also need instructions.

So I'm wondering if it would be possible if you could explain how to build this app? I have Xcode 12.0 installed and am familiar with Swift and SPM.