Rodina, a space exploration game, is now being offered for sale in an pre-release state. Taking a tiered, "pay-what-you-want" pricing structure, you can have the current build by spending a minimum of $1, but access to updated versions of the game (including the final version) will require a minimum price of $15.
And if you're balking at paying anything to play it, there's also a meaty, one-hour time-limited demo which you can check out before plonking down any cash.
Check out the above video to see some of my experience with the demo. As noted, I used the controller, though I have tried keyboard and mouse also and the ship is pretty challenging to control with either scheme. I'm not sure I have what it takes to get good at it, but there seems to be a whole vastness of space out there to explore, so I'll probably keep trying.