Recommendation engine: Downvote any game you've heard of before
This might be a slightly unusual attempt at a prompt, but might draw some appealing unusual options.
The way it goes: Suggest games, ideally the kind that you believe would have relatively broad appeal. Don't feel bad about downvotes, but do downvote any game that's suggested if you have heard of it before (Perhaps, give some special treatment if it was literally your game of the year). This rule is meant to encourage people to post the indie darlings that took some unusual attention and discovery to be aware of and appreciate.
If possible, link to the Steam pages for the games in question, so that anyone interested can quickly take a look at screenshots and reviews. And, as a general tip, anything with over 1000 steam reviews probably doesn't belong here. While I'd recommend that you only suggest one game per post, at the very most limit it to three.
If I am incorrect about downvotes being inconsequential account-wide, say so and it might be possible to work out a different system.
Avorion - In which you command and build a spaceship designed by yourself (or others on the internet). Soon you have AIs you command and space stations you own. The game allows you to lean as much or as little as you want into the fleet command and economy aspects. If you want, you can just pilot one big-ass ship and do it all alone.
I had a good amount of fun with this game, it's a shame I have to downvote it. It was a little difficult to get into at first, but I stuck with it and had a lot of fun. I chose to develop a big-ass ship like you speak of and eventually became a lumpy Death Star knockoff.