The first film surprised Hollywood, critics and audiences by actually being pretty funny and making a mint at the box-office, so the fact that we're seeing a sequel to 21 Jump Street will shock no one.
Obviously jumping on a crowded schedule of a twice Oscar nominated leading man, a heavily in demand pin-up movie star and co-directors who just turned down Ghostbusters 3 has caused everyone to rush 22 Jump Street; because while it has some funny moments, it's ultimately the same couple of jokes underlined too many times.
Since we last met them, hapless but somehow effective cops Tatum and Hill have continued to go deep undercover; infiltrating a dangerous Mexican gang at the beginning of the movie. They (kind of) return to their roots when they're sent to find the dealer of a nasty drug circulating at a local college that apparently caused a student to commit suicide. Deep cover once again involves them reliving their younger days with retrospect as a buffer. So, y'know, Hill sleeps with a beautiful student and Tatum is good at being a jock.
Off the bat 22 Jump Street lets us know it's nothing if not self-aware, as their boss tells them that this case is basically the same case as last time. Just bigger. An obvious nod to sequels generally costing more money to make and not being as good. Which it isn't, but that's fine, you get that everyone knows it's not going to top the original. The laugh ratio here is just diluted massively and the end result bloated and indulgent.
Almost backed into a corner by its own success, this fledgling franchise couldn't really go past the 'back to school/college' concept; it would be a different movie and that's a risk they obviously weren't willing to take. But while you can forgive a cloned plot, the gags just aren't as plentiful and are at times plain desperate - see the Octopus attack, Tatum inexplicably doing parkour, and Ice Cube's grating snarly face.
That said Jillian Bell is an absolute stand-out as the weird roommate, providing genuine laughs from the same gag - something the writers could learn from.
Bad Neighbours did the college clash thing far better.