Try Rodina. Very unique and interesting seamless “open solar system” game made by a single developer. Comes with a fun ship interior builder. It looks very bland and dated on screenshots, but feels awe-inspiring to play, creating a sense of scale that I have not seen anywhere else. It feels almost 3D even on a flat screen.
Rodina does not have a ton of actual content, but that’s not necessarily a bad thing. Also, you can propel yourself around space with a fire extinguisher, which automatically makes this the best space game in history.