http://www.rottentomatoes.com/m/muppet_treasure_island/
http://www.crankycritic.com/archive/muppettreasureisland.html
http://www.dvdizzy.com/muppettreasure.htm
http://www.grouchoreviews.com/reviews/2424
Out of all of the reviews, I liked the one on Rotten Tomatoes the best. All the reviewers have the film a positive rating though some mentioned that some of the gags were recycled from other memorable Muppet moments. To quote the guy in Rotten Tomatoes
Long-time followers of the Muppets may find the film less fresh than Jim Henson’s original creations, but the combination of old-fashioned storytelling, intriguing design, and clever humor will undoubtedly amuse younger audiences.
I haven’t been following the Muppets as much some people older than myself but I’ve been a long time fan. I’ve seen them on many other movies before and the reviewer does have a point. The humor is great and the typical expected Muppet gags are there as well. The wording is perfect for a parent to take a look at and decide if their child should watch it. It caught almost everything I’d written except some of the reviews felt a little more impersonal. I was more attached to my review as opposed to the movie critics.
Michi's World 