It depends on which VR headset they got. Do you know if they got an oculus or a playstation VR or like a HTC Vive? As far as the headaches go, when I first started using mine there was a little bit of headache/vertigo after I was done playing until I got used to the adjustment. As far as games go that really depends on two things. Which headset you got and how old they are. There are tons of options for any of them. Oculus has some really cool puzzle games as well as exploration. Im not as familiar with PS VR or the HTC ones. A buddy has the PS VR and he has a pretty decent library of stuff to play. Find out which headset they got and what their likes are and I could give some better recommendations. Beat Saber is tons of fun if a little on the silly side and I think thats available on multiple platforms. If you have playsation VR ( PS VR ) fruit ninja VR i pretty fun and so is Angry birds VR.