UFO is essentially a puzzle game with adventure elements (navigating a character). The hero must travel to different rooms in the apartment building at different times, trying to snap the perfect picture of the invisible alien. The player is given a time limit and a picture limit (ten pictures per visit). Afterwards, the hero has to return to Mother, who will eat the negatives (really), produce pictures, and then decide whether they are suitable or not. Each successfully taken photo opens a new area and/or a new time of the day in the apartment block.