I didn't know there was a fourth Home Alone movie until I watched it on TV the other night, and quite frankly, that was two hours out of my life I'll never get back.
Apparently the writers paid very little attention to the original movies in regard to the family members and chronology of their lives. In the first movie, Kevin McAllister is eight years old when he is first left home alone as his family go to Paris for Christmas. He has two sisters and two brothers.
The next year the family heads off to Florida with Kevin presumably in tow, only to learn he has boarded the wrong plane and ended up in New York City. This would make him nine years old. In both movies, he deals with Harry and Mary's inept attempts to burglarized first his home and then Duncan's Toy Chest.
Therefore, how could Kevin be nine years old in the fourth movie at home in Chicago with his parents being separated at the time with only two siblings?
As for the plot, it is fairly lame and predictable without any of the charm of the first two. The only real surprise came from learning who the real mastermind was behind the attempt to kidnap the prince. The only real consistency I saw in the movies was Kevin's love of Christmas trees and the viewing of Frank Capra's It's a Wonderful Life.
The blurbs I read said Kevin was trying to get his parents back together, which really wasn't present in the movie. He seemed reconciled to the fact that his dad was living with another woman who was supposed to become his new step-mother. He also went to his father's for Christmas because of the torment his brother Buzz gave him and his mother's lack of intervention in the matter. Kevin was never really left "home alone" in this film as he was surrounded by the housekeeper and butler along with his father, his girlfriend, and at times his mother, brother, and sister.
Frankly, I wouldn't bother wasting my time watching this movie again unless it was the only thing on at three in the morning, and even then, I think I would just pop in a DVD of something else. If you want to enjoy the classic movie, just watch the first and second ones with the original family. Macaulay Culkin is the definitive Kevin and there really is no compare.