One thing to mention since I couldn’t since I was on my phone which died, is that while you’ll be looking at the entire template, only use it for the user authentication and patch/download part of it. You won’t be designing a full “MMO”.
Basically, the flowchart would be:
Backend:
- Set up user (client) account. Username, password, simulation title, description, (other fields), download link
User(Client) Facing:
They run the launcher, and put in their username and password. The launcher then downloads and installs the “game”. At that point, everything is on their local machine.
I would suggest tying in a machine spec check to make sure that the client is running the necessary hardware. If they’re not, then a dialogue box comes up and warns the user/client that they are not using a powerful enough machine.
Or another way (easier for 1 shot deals), is to create the simulation/game/whatever you want to call it, package it and upload to google drive, get the download link, and then send them the link to download 
Of course though, that isn’t exactly “professional”.