The Lab is a free compilation of virtual reality experiments from Valve, the company behind Steam and the Half‑Life and Portal games. It was released on 5 April 2016, just as room scale VR headsets first arrived in homes, and was designed to show what the new technology could do. You stand in a hub inside Aperture Science, the laboratory from the Portal series, and step through doorways into eight different experiences.

Almost a decade on it is still one of the most highly rated VR titles on Steam, with 95% of more than 4,400 English language reviews positive. Its strength is polish: every station teaches a new way of interacting, from picking things up to aiming a bow, and the whole collection works as a friendly, confidence building introduction for anyone who has never worn a headset.

The other four are games: Slingshot and Longbow are physics based target and castle defence challenges, Xortex is a retro style space shooter, and Secret Shop is a whimsical fantasy shop with hidden surprises. They are great fun and teach good VR skills, but they are entertainment rather than learning.