I once checked this out on a trip, in my hotel room, knowing nothing at all about it. It turned out to be a good story, part-way relatable to yours truly, with a solid cast of likable, as well as despicable characters. That was one of my best viewing experiences, especially in the context of taking the trip because I was trying to get my mind off things.
We are introduced to the awkward, 14-year-old Duncan (Liam James). He doesn't really seem to fit in anywhere, and is reluctantly dragged along on a beach trip with his Mom (Toni Collette), her boyfriend, Trent (Steve Carell) and his daughter, Steph (Zoe Levin). On the way, Trent tells Duncan that he wants to see his personality, and even physical appearance improve over the course of the trip. So yeah, we immediately hate this guy.
While there, Duncan is having an awful time, wanting much more to stay with his Dad, and not have to deal with Trent's asshole comments, or Steph, living in her one-dimensional world of "bully cheerleader". It doesn't take long until Duncan gets fed up, and bikes over to the local water park, The Water Wizz, to get away from things. Here, he meets Owen (Sam Rockwell), a cool, trouble-making type who takes Duncan under his wing and shows him a thing or two about confidence. He lets Duncan work for him, and along the way, they learn from each other, and help each other grow up a little bit.
Duncan needs to work up some courage to talk to the girl next door, Susanna (AnnaSophia Robb), and be able to stand up to his stepfather. Owen, on the other hand, needs to just grow up a little bit for Caitlin (Maya Rudolph), who works with him, so often cleaning up after him. But the story doesn't really stop at these two, either.
Still told through Duncan's perspective, we also get a lot about the relationship between Pam (Duncan's Mother), Trent, and Trent's friendships with the locals. Neighboring them is the alcoholic Betty (Allison Janney), Mother to Susanna and the young Peter (River Alexander). Party couple, Kip (Rob Corddry) and Joan (Amanda Peet) are added into the mix as well, and when all together, this movie is gonna remind you of some of the fun beach or camping trips you may have been on with a big group. So oddly enough, it manages to show us the enjoyment of a beach trip mixed in with how much it sucks for our main character.
I have to say that I relate largely to Duncan in this movie, especially being that awkward kid, myself, back in the day. I had terrible trouble talking to girls, was unpopular, very shy, and much of the criticism towards me was very back-handed, much like the way Trent talks to him in this. So there's a good chunk of this that's almost bias, being able to empathize with him, perhaps a little bit more than others. But even still, this is a great movie for anyone who might be feeling down and out on themselves. I can say with all honesty, it worked for me.