Twenty questions is a simple game which students love. Try 20q.net things) or Akinator (people) and get the computer to guess. (choose an easy item like "chopsticks" the first time so the computer will have little difficulty). Appoint one student as MC to read the questions. Full rules here.
If you present the class with this game here, they'll get the idea of how the game works.
This attached game from Andrew Finch's great workbook Tell Me More, is a simple version (buy the book, really good!). Basically, students can play this game with any selection of flashcard pictures. Simple to set up and lots of language use....
Also use the template if you want to make a ppt game. Or have students use the tracking sheet and make questions before or during the game and record the answer.