I couldn't find the 4th crystal thing. As already noted, a map showing at least where you've already explored would be helpful. I liked the thing at the beginning where you were looking at your laptop in the first person with those delightfully silly hands in front of you. It would've been good if there were more elements to keep the player motivated to carry on playing e.g. interesting graphics, story, music etc. The visuals and sounds during the actual gameplay, while reasonably polished, felt a bit mundane to me.