22 Jump Street plays like an in-joke, a movie that parodies not just itself, but the entire process in which movies (namely sequels) of this nature are produced. With the exception of a fucking hilarious twist involving Schmidt's (Jonah Hill) new girlfriend, the film doesn't exceed the original, but stays on par with the amount of laughs. That's not a bad thing - in fact, it's the greatest compliment I can give this totally entertaining movie.
Again, Channing Tatum in his Jenko role is the best part of the film, which doesn't come as the surprise that was evident when he shocked everyone by how funny he was in the first film. His chemistry with Jonah Hill's Schmidt remains the highlight for the continuous comedy from the two guys. The movie stays focused mainly on the two of them, and never strays from the routine that made the first movie so funny.
Now, I usually have a problem with sequels that emulate the original too much to the point that we're essentially seeing the first film again (The Hangover, Part II I felt suffered because of this - took what was funny, but made it darker and more disturbing in the context of the exact same story). With 22 Jump Street, we are told right after the opening scene just why the film is going to do exactly the same thing as the previous one. Schmidt and Jenko's supervising deputy chief (played again by Nick Offerman) does the same breakdown he did in the first film - as a self-aware in-joke - by verbally laying out the entire groundwork for how the story will play out, and essentially explaining to the audience the mindset behind the producers as to why this film was made in the first place.
The "Jump Street" program has an upgrade, mainly because the "budget increased with the success of the first one", and is moved to a better undercover location - conveniently across the street at 22 Jump Street. Their captain, played again by the always-funny Ice Cube, is as dirty as ever, and has some of the best scenes of the movie.
As was foretold in the opening scenes, the movie plays out much the same as the first, with another drug ring that must be infiltrated, but this time at a college setting. Another drug, another school, another building of trusts while gaining mistrusts, etc.
Essentially, if you liked or LOVED the first film, you will like or LOVE the second one. The movie doesn't try to be anything more than the first one was. It doesn't go darker like The Hangover series did, but instead strives to be just the same, giving audiences EXACTLY what they'd expect if they approved of the first one. There are a couple slower moments in the middle of the film (much like the first one had), but once the action picks back up, all is forgiven.
Also, stay for the beginning of the credits. If you have to piss, hold it, because some of the funniest moments of the film come from the self-awareness of the action that takes place for the first couple minutes of the credit scroll. Literally pokes fun at the shit that has been annoying many film lovers for the past decade-and-a-half, and in turn closes the film in the most complete and perfect way.
"If you are in need of a good time, sit back and enjoy as this movie fulfills your need to laugh like an idiot."