The game is centred around a research scientist called Travis who works at a high energy institute experimenting with dense matter and the theoretical creation of black holes for interstellar travel.
You are Travis, arriving in a huge world built of bubbles. Travis is luckily rescued by a friendly denizen of this bubble world, one of the rare free floating air bubbles. The bubble is able to help him in a variety of ways. he can use it to negotiate the world, and to protect him from the hostile environment.
The only hope of survival is to find the right radioactive deposits that will allow Travis to use the projector to go home again. Meanwhile he can use his equipment to help defend the bubble, by causing it to manipulate the surface of the bubble and send shots streaking across the void.
Travis can wander around a level freely to search for the deposits that will send him home. There are 5 sections to the world where radioactive deposits of the sort needed can be found, starting in the core of the bubble world where Travis arrives. Travis must traverse each level, looking for all the deposits that exist there before he can afford to waste the energy for the short jump to the next section.
When all of the radioactive deposits on a level have been collected, the level fades away as Travis teleports into the unknown.
Note: this game came in many different colours for the instruction manual/cover page insert including yellow (pictured), green and even red.