My seven year old son Damien and four year old Daughter Willow ride the roller coaster through the EPIC Citadel with the Oculus Rift.
http://www.mtbs3d.com/phpbb/viewtopic.php?f=140&t=17157
Please note that it is not advisable for young children to use the Rift for extended periods, or even to use it regularly. This was only a short turn they got as they keep asking to have a go.
