Dave (Jason Lee) decides he, the chipmunks and the chipettes need a vacation and so book them on a cruise. Of course take the Chipmunks and Chipettes on board a ship and there will be chaos with Alvin at the heart of it. But their former nemesis Ian Hawke (David Cross) happens to be working on the cruise ship and on spotting the furry critters is looking for any excuse to kick them off. He needn't have worried as when Alvin goes kiting he and the rest of the Chipmunks and Chipettes get whisked off the cruise ship and they all land on a remote island forcing Dave to talk Ian to try and help him finding the missing furballs. But the Chipmunks and Chipettes are not alone on the island as they meet Zoe (Jenny Slate) who has been stranded there for maybe 8 or 9 years and to make matters worse Simon gets bitten by a spider and when he comes to thinks he is Simone a French chipmunk.
Okay dokey then "Alvin and the Chipmunks: Chipwrecked" the third of these live action Chipmunk animations and in one review I saw referred to as a pile of chip. And I can see how someone might refer to "Alvin and the Chipmunks: Chipwrecked" in a derogatory manner especially grown ups who experienced the Chipmunks when they were children as this third movie is weak. It basically consists of some movie cliches, a parody of "Cast Away" and what can only be referred to as the "Chipmunks" do "Glee" as every few scenes we get the Chipmunks or Chipettes singing and dancing to some what was then current music. Basically everything which grown ups would have loved as children is missing in this movie.
But trying to think like a young child and it is the young child which "Alvin and the Chipmunks: Chipwrecked" is made for and part of me has to say it works. The bounty of musical elements which feature the Chipmunks and Chipettes behaving like the kids from "Glee" will probably entertain the younger audience as will the easy to follow cliches which they will be able to understand. And whilst the comic chaos border on the moronic for grown ups I would hope children would be amused by it especially Jenny Slate who plays it over the top island crazy.
What this all boils down to is that "Alvin and the Chipmunks: Chipwrecked" is simply a third movie which just decided to target the younger audience rather than any grown ups who had watched the Chipmunks as children. It is why for adults this third movie doesn't work but for young children it probably still does.