This movie is a delightful romp with a lot to offer. Zac Efron is amazing in his part as Mike, with talent to burn. He's sweet but takes no prisoners when dealing with ruffians, and his moves on the dance floor and his agility with a basketball are equally impressive. He demonstrates his acting chops in this movie as well, going from winsome to tough to romantic and all-around likeable without ruffling a feather.
Thomas Lennon as his quirky Star Wars sidekick is hilarious and adorable. His role is more than a supporting one, as his storyline is given more space than one might expect, but it adds a lot to the movie's humor and keeps it lighter than it would be with the sometimes gritty problems that Mike faces with his children's issues and the difficulties of trying to recapture his wife's love.
Matthew Perry's part is too small to do him justice, but he fulfills it well. The movie focuses mainly on Zac Efron's part in regaining what the adult Mike, played by Perry, cannot get back on his own.
This movie is so enjoyable that you're willing to suspend disbelief when you need to. Mike's wife, for example, seeing him exactly as he looked when he was a teenager, is very slow in picking up on the fact that he IS her husband as a teenager, and she seems blandly accepting of the story concocted by Lennon's character that the young Mike is his son. Of course, the transformation from 30-year-old to 17-year-old Mike is another leap, but the movie is so engaging that you don't mind. Watching Mike get back at the bullies picking on his teen children is satisfying, and his efforts to extricate himself from sticky situations are humorous.
Anyone who ever thinks about those teen years and wishes there were a way to go back and relive them again will enjoy this movie. There's plenty of action, some tender moments, and enough craziness to keep you thoroughly entertained. It gets my vote, and I'll definitely watch it again.