Learning outcomes of games, expecially for exam review, are as good as or better than outcomes from "traditional" ways of instruction. So, we decided to use the American game show "Jeopardy" as inspiration because it's a great way to practice definitions and mathematical concepts. Jeopardy games have five categories, and each category has five questions. The questions are worth between 100 and 500 points, with the idea that the questions that are worth more points are more difficult.
Using a blank template from the Jeopardy Labs website (I highly recommend this site; it has a ton of pre-made templates for all subjects), I created Jeopardy games for 2nd year and 4th year exam review. See the 2nd year game, which was about square roots, here.
It took the students a bit of time to understand some of the specific rules, like the fact that they had to wait for me to read the question before they could "buzz in" to provide their team's answer. But in the end, the game was a great way to combine math, English and, most importantly, a bit of fun in the classroom.