Very enjoyable and surprisingly atmospheric.
The minimalist rooms make it easier to figure out what you have to do. I figured out the navigation in seconds and have no problem with the back button in the corner, it helps prevent moving out of the room by mistake. The graphics are very simple but the effect is good. The only thing I would change is to have the mouse pointer change when over the light switches in the dark rooms, I don't enjoy clicking the entire screen just to find a light switch (I resorted to the tab key). The puzzles are a little frustrating when they reset but the options in each puzzle are limited so it doesn't take long with trial and error. Some humour would be great!