While some developers have recently gone towards a philosophy of making a bunch of smaller releases and dropping them on the App Store quickly, German developer Fishlabs has done the opposite. It's focused on one huge game, Galaxy on Fire 2, and spent the last year expanding and perfecting it. The app is on iOS, and it's just a brilliant game for the iPad, if you haven't seen it yet.
Galaxy on Fire 2 HD is also available on the Mac, and Fishlabs' hard work is evident from the beginning. As you can see above, the graphics are phenomenal. What you'll get is open-world space exploration, combat and trading game, with a huge galaxy to explore, a large story to play through, and plenty of things to do, from full combat missions to simply flying around the galaxy and trading or exploring. This game's been polished and re-polished and then some. As an original title on the Mac App Store, it doesn't get much better than this.
The one issue I have is in the voice acting. Some of it can be a little wooden, and because the developer is European, the accents are a little strange. But that's just a small caveat. If you haven't played this one yet, and especially if you have a big bright MacBook or a new iMac to play it on, definitely pick up Galaxy on Fire 2 HD. It's on the Mac App Store for $9.99.