A great deal of unrealized potential.
There are guns that hint that there might be some sort of combat. There are hidden sections in a few of the areas that hint that there might be some scheme to "break free" of the standard areas. There is dialogue that hints that this is not the most legitimate facility and that you should be attempting to break free. There are courses that suggest you should be able to fly outside of the course itself.
None of this is ever realized in any parts of the game I ever came across. There is NOTHING to shoot, not even a single thing in any area that even responds to being shot, not even leaving burn textures behind that would at least allow you to pretend you were shooting targets. There is one area that doesn't seem to have any bounding box,(space) but all that does is make it almost impossible to find your way back if you go too far.
However this may all change in a future update. For what it is, the controls and gun/flight mechanics are... interesting. They could stand to change the angle the the thruster gun objects are in relation to the Vive wands, which could make them more comfortable to use, but for the most part, the flight itself is an enjoyable experience. I use a constant floor bounding area in my Vive settings though, which may have helped reduce nausea, as the flight is apparently too much for some people to handle, at least from what some of the discussions and other reviews have mentioned.
I recommend this game, really only because it is free. If it cost even a single dollar, I would expect at least some sort of content (missions to carry out, targets to shoot, secrets to find? something?) before it would be worth that investment, but for free, the only requirements I have behind my recommendation is that the VR is stable and basic controls work as expected. That much it succeeds in with flying colors.
Just as a side note, the highest speed I was able to achieve was around 1300km/s. I didn't notice any particularly effect approaching a blueshift.
