If you're determined to enjoy Arnold Schwarzenegger flailing around in a classroom full of (supposedly) kindergarten-age kids, then you will, regardless of the stupidities of the plot and the taking-the-law-into-your-own-hands violence that's a bad lesson for kids or adults who watch this movie.
The only remotely funny scene in this "comedy/drama" is stolen from Woody Allen's Annie Hall, when the kids face the camera individually and tell what their daddies do. (Identical twins speaking in unison: "Our mommy says our daddy is a sex machine." Remember "I used to be a heroin addict, but now I'm a methadone addict" and "I'm into leather"?)
But Schwarzenegger gets the kids to mind him by putting up a sign on the blackboard declaring his classroom "Police School" and teaching the five-year-olds to march through the playground. The Fuehrerprinzip at work in our schools. Is this part of Bush's No Child Left Behind? Marching? Did Ivan Reitman really make this movie?
The happy ending is Schwarzenegger's Kindergarten Cop splattering a young boy's father's brains against the bathroom wall at school PRACTICALLY IN FRONT OF THE BOY. Then the principal lets him come back to the school as a teacher after he's put all the kids' lives at risk. If the writers had thought about the story for a few minutes more they could have come up with a climax that made Schwarzenegger the hero-savior but wasn't as unbelievably (if still gratuitously) vicious. But I guess that doesn't matter in Schwarzenegger movies.
Movies aren't real life, but what kind of people put this stuff out for people to be entertained by? Best of luck, California.