The movie mainly seems to be making fun of everything (including teens' reliance on their phones) and/or celebrating stupidity and fighting.
Characters are killed by small monsters that enter via their bottoms. Knives are drawn but not used. Characters use martial arts-style yoga to defeat a giant monster. Small monsters stepped on, microwaved, smashed, and whacked every which way. Minimal blood and gore, all of it very fake-looking CG. An explosion. References to Nazis, with Nazi imagery.
References to sex between an adult couple, viewed as "gross" by the teen characters. A woman opens her top, showing her bra, and asks if a man wants to play in her "bouncy house." A young man removes his shirt, and the teen girls comment on his cute nipples. Discussion of a woman's period. A drawing of testicles, used to deface the cover of a book. The girls discuss how far they're willing to let boys go ("second base").
Multiple uses of "s--t," in English, as well as French ("merde") and German ("scheisse"). Also: "bitch," "ass," "d--k," "goddamn," "butthole," "suck," "butt," "poo," "skeezing," "damn," "gay," "testicles," and middle-finger gestures.
Smartphones used frequently, with references to Instagram and/or Snapchat-like apps.
References to teens drinking at a party, but nothing is shown.