If you ask me to make an account before I can see your content (even if it looks interesting) that's a turn off and I'll go somewhere else. Maybe have a button at the top that says "explore as guest" or something like that?
Also you should advertise that this is an open-source project on the landing page, as that may cause more people to be interested in trying it out.
Even for buttons I've seen small matrix displays beside the button (or even underneath its plastic shell) acting as the label and indicator. This prevents the need of having the programmable buttons next to the screen, but at increased cost.
For the space combat FPS I think you're talking about Angels Fall First (https://store.steampowered.com/app/367270/Angels_Fall_First/). Players start on a capital ship and can walk around, fly fighters, and attack as well as board their enemy.
The old Battlefront 2 also had a (simpler) form of this type of capital ship combat, where the bases were the ships and players would dogfight in space and attempt boarding actions.
That's was what came to mind for me as well. For digital you simply can't beat the cost of a mass-produced FPGA over having custom silicon fabricated (at small scale). Not to mention the additional design costs, EDA tool licensing, etc.
Now for hardened applications, these large nodes have their uses. But that's a very niche case.
Also you should advertise that this is an open-source project on the landing page, as that may cause more people to be interested in trying it out.