Method 1: DIRECT DOWNLOAD
Installing an era game is piss simple. They're all portable, so all you need to do is decide where to put it. It really doesn't matter, so long as the directory's empty.
Once you've decided on a spot, just unpack the archive you downloaded there and you're good to go. It should look something like this afterwards. (photo is TW)
When you update, you MUST NOT UNPACK OVER AN EXISTING INSTALL. I REPEAT: YOU MUST NOT UNPACK OVER AN EXISTING INSTALLATION.
Doing this will break something, as between versions some files are removed all together, instead of just modified or added. What you should do, is either make multiple installation directories for different versions, or just delete the one you have (except for your sav folder, if you want to transfer saves) and reuse the directory.
Method 2: GIT CLIENT
Installing a game with a git client is a bit more involved, but updating requires virtually no effort. It does make you register for two accounts though, but all they need is an email. What you need to do first is grab a git client. The most noob friendly one I've found is GitKraken, so it'll be the one the guide's based around. Go here ( https://www.gitkraken.com/ ), and download the client. It's free. Once it's downloaded and installed, open it and you'll see this window:
Note that that first button is for GitHub, not GitGud. Our repositories are on the latter, which is why you need to make an account for both the Git, and for the client.
Once you've gotten the GitKraken account made, next step is to create an account with GitGud/Sapphire here: https://accounts.sapphire.moe/app/users/add
Note that sapphire sucks ass and is down a lot, so if you suddenly can't log in wait a few hours, it'll fix itself.
Once you've got both accounts set up, navigate to the Authentication tab in the GirKraken client Prefrences menu, which you get to by clicking the menu button to the right of your user icon in the top right, and generate a SSH key by clicking the "Generate a new Private/Public Key" button. They'll save to file, so just pick somewhere to keep them. Once you have that, go into your git user settings, and go down to SSH Keys. Paste your public key in here, and give it a name. This will allow you to clone via SSH, which is the easiest method. After you've done that, navigate to https://gitgud.io/era-games and pick a game, for this guide we'll use TW. Once you're on the game's page, you'll want to click the clone button, and copy the clone with SSH link.
On your GitKraken window, press either the folder icon in the top left, or the "Open a Project" button in the center of the screen. Click Clone, decide on a directory, and paste the SSH clone link into the URL field. It will automatically make a folder for the game, so you don't need to do like "Games\Era\TW", just make it "Games\Era" and the client will fill in the rest from the url. After that just press Clone.
You'll see a blue box in the top right of the client that shows the download progress, wait until it finishes. TW isn't a very big game so it shouldn't take more than a few minutes, even on the most Australian of internet connections. After it's done, a banner will pop up at the top of the client, saying something like "Clone successful" and two buttons, one opens the clone and the other dismissing the banner. At this point, you're done with the installation, and can start playing. When you launch the program from here on out, it should automatically check for updates, and you can apply them by pressing the "Pull (fastforward if possible)" button at the top of the window with the repo opened.