The original Predator film took place in the jungle, an entirely logical setting that took advantage of the title killers skillset and the idea of "the hunt." The sequel decided to change things up by ditching the green jungle for the urban jungle. Taking place in Los Angeles, Predator 2 was a weird beast of a sequel that was poorly received, but one has to wonder if things would be different if the writers had gone with one of their earliest ideas. Originally, they were thinking about setting Predator 2 during World War II, where the alien would have hunted American and Nazi soldiers in the snow.
We also had an idea about doing a World War 2 version in the Battle of the Bulge, in the middle of the winter. A German foot platoon and an American platoon separated, and had a stalemate fighting each other off when the Predator shows up. They have to join together to defeat it. We thought the snow Predator effect would be quite different.
The original plan for Predator 2 was for Arnold Schwarzenegger to return, using salvaged Predator tech from the first movie to continue the good fight. However, Schwarzenegger didn't want to come back, so the writers had to scramble for a new idea. They ultimately settled on Predator vs Danny Glover in LA, but the sequel could have potentially been much different. At a screening celebrating the 30th anniversary of Predator, writer Jim Thomas told the crowd in attendance (via Facebook) that they considered setting Predator 2 during the height of World War II. The idea was to unleash the Predator on a group of waring American and Nazi soldiers who had reached a stalemate and would have to team-up to kill the Predator. The writers liked the idea of seeing the Predator in the snow, but ultimately decided against the idea.
It's a cool sounding and imaginative concept -- at least compared to what they originally went with -- but it's not perfect. Not only is it a huge departure from the first Predator (this should be like Predator 6 after all the other ideas are gone), but it sorta kinda portrays Nazis as the good guys in the context of the film by making them team up with America to kill the real villain. You're supposed to sympathize with the humans the Predator is killing, not root for Predator to win. But it doesn't matter because they went with gang wars, voodoo, and Gary Busey in LA, so it worked out.
As a reminder of what Predator 2 was like, check out the trailer for the sequel.