Star Valor does look great. If you’re on Mac or Linux you can play Endless Sky or Naev, which are both free. Or outside Steam try Starsector, which might be the best 2D space game on the market, or The Ur-Quan Masters; a continuation of Star Control 2 and also free.
That’s a tough question. There’s a handful of 3D space combat games like Everspace, Starlink, or Manticore: Galaxy on Fire. There’s also bullet hell games like Galacide and AstroWings: Space War. But none of those are quite like the more open top down games above. Your best bet to find something might be to ask on a larger Nintendo forum. I hope you find something!