The PowerPoint games I've developed here could be used in two ways. Either a zippy fun thing in the last few minutes of the lesson to test what you've studied in the lesson, or an activity which could lead to discussion of grammar/pron/vocab. The template for these games will allow you to make your own.
One word of warning: in my experience, interactive whiteboards don't react well with some types of animation in PowerPoint. So, I would advise using the mouse to click on questions in PowerPoint rather than the whiteboard pen, unless you have super-duper whiteboard technology.
Game 1: odd one out / multiple choice quiz
One question, four possible answers. You could use this as a multiple choice quiz, or as an odd one out activity. Below is an example game for pronunciation, and the basic template.
Game 2: who wants to be a millionaire
Again, one question, four answers, but this one is based on the famous game show. The "lifelines" can't be put into the PowerPoint itself, but you can take out two answers yourself (50-50), let the class vote (ask the audience), and improvise for phone-a-friend. Use the template below to make your own.
Game 3: treasure hunt
You don't need to adapt these PowerPoints - the only preparation you need here is a handout with questions. Teams discuss the questions together, and then you ask them to choose a question to answer.
If they are right, they can click a shape to reveal what is behind it. They get a point if it is the treasure. (in the picture here, Easter eggs).
Game 4: anagrams
A quiz rather than a game, but it's a great way to review language. Type your anagram into the anagram box, type your answer into the answer box, then drag one over the other. Copy and paste the slides to add more anagrams. If you want, you can add a question in a text box (as in the image here), or to save preparation time, you could ask the question verbally. This works really well if you get the students in small teams and give them buzzers.
Make your own PowerPoint games
If you want to know how to make your own, have a look at these instructions videos