This is an add-on for the game, and I'm pretty much done with it. It's a mod that adds an extra health bar to the game, and the developer is still going to try and update it when they have the time. 

It is a simple addon and it doesn't require any kind of installation or anything like that. If you want to download it and try it out for yourself, you can do that by downloading the file from Nexus Mods and then installing it. The instructions are pretty easy and you will not need to change anything in the game.