The first five minutes of Solarbabies (1986) sets up an intriguing future in which water has become scarce, and society shattered, via a well done narrative sequence.
After that, it’s about how cool it is to travel on roller-skates in the desert and encounter an unexplained alien being, shaped like a crystal ball, which becomes the friend of all the good guys.
The actors give it the old college try, but this story is nowhere near college level. Avoid! Avoid!