Noctis

Noctis is a game that is very similar to Frontier: Elite II and its sequel, but it is also very different at the same time. While the Frontier series is focused on combat and trading, Noctis is more geared towards space exploration. Considering that Noctis seems to have been conceptualized and designed by a single person, the results of the effort exerted into the creation of this game is nothing short of impressive.

In Noctis, there is no sentient life in the galaxy you are set to explore. Even your own race has disappeared, only leaving behind a small fleet of manned scout ships whose mission is to catalog and explore all the stars in the galaxy. You, of course, control one of these scout ships.

You can travel to any star you want to, at any time, provided you have enough fuel (as in Elite and the Frontier series of games). There are 11 different types of stars that you will see in this galaxy, and each star system out of the possible MILLIONS that you can visit have their own unique system of planets and moons, which you can land on and explore most of the time (landing is handled by a method that is similar to the landing system in Starflight). The star types range from S00 class stars, which are similar to our sun, to S11 stars, which are highly radioactive pulsars. You can label the stars and planets in most of these systems with any name you can think of, provided it's not a real star or planet name from our galaxy, or if the name hasn't already been taken by another explorer.

When I say "taken by another explorer", I mean that you can upload the names of the planets and stars you've explored, and also upload any notes you've taken regarding the explored celestial objects to the official website, which will then get released in a download that will also contain notes from other explorers. You can read their notes about the planets and stars they've discovered once you integrate the information into your copy of Noctis.

Noctis is a game that is played in real-time and has a persistent universe.