It is a common problem the first time you play a VR game with smooth locomotion. The good thing is that as long as you take breaks and come back to it you will (usually) get over it. It happened to me when playing Boneworks for the first couple of times but now I don't get it even in the most extreme, fast moving games. The only thing that will make me sick is if the display freezes or stutters really badly which is quite rare.

For games without smooth locomotion, VR sickness usually isn't a problem unless it's a crap game that stutters or has other problems.