I don't know if any of you have heard of the work-in-progress game Limit Theory, but it's looking kinda incredible right now. It's a procedural space sandbox game-pretty much the only things that will be hard-coded are the interfaces and the sound assets, as I understand. It had a highly successful Kickstarter, and since then the developer (singular) has made daily dev log updates and releases a development update video the last day of each month. here's the latest one: Even if you're not interested in the game itself, if you work with coding I would recommend watching from about the 14 minute mark- the part about the data editing.
It is an open sandbox game, but there's also RTS and even s bit of 4x in the mix. In retrospect, this probably wasn't the best update video to introduce it with...
It's a single player game. The $20 Kickstarter tier got you the game, so I figure release price will be 25 or 30. I dunno for sure though.
