Quick recap
The movie opens by explaining it's the film that made Andy want a Buzz in 1995. Space Ranger Buzz Lightyear botches a maneuver and strands his ship and crew on the planet T'Kani Prime. To fix it, he test-flies a hyperspeed fuel, and every four-minute flight costs four years on the planet. His friend and commander Alisha grows old and dies while he keeps trying, now with Sox, a robot cat. When he finally succeeds, Buzz jumps another 22 years and finds the planet invaded by Zurg's robots. He teams up with Izzy, Alisha's granddaughter, and two clumsy recruits. Zurg turns out to be an older Buzz from another timeline who wants to undo the original mistake, even if it erases everyone's lives there. Buzz refuses, destroys the fuel and accepts the planet as home.