Overload is a spiritual successor to the classic Descent series, made by some of the same developers. They're doing a Kickstarter campaign to get the game, and it's in the final stretch. They released a playable demo for the Rift, and I got right on that because I love the heck out of Descent.
The campaign is here: https://www.kickstarter.com/projects/revivalprod/overload-the-ultimate-six-degree-of-freedom-shoote/posts/1514273
Please, please please help these guys out! It's awesome!
(If you're wondering why I stopped playing in this video - I got a bit motion sick, my computer doesn't quite meet the Oculus recommended specs, and the demo, as they openly admit, is an unoptimized prototype)