I confess, sometimes we English teachers use games as anything other than what they should be used for. Sometimes we use games a reward for students who've completed a certain segment of study. Sometimes we use games to give the students a break from long, tedious minutes of English cramming sessions. Sometimes we use games just to kill time. It is my belief that games should NOT be used merely for such purposes, but rather for the purpose of assessment.
Some games are better than others.
Here is some criteria to determine if a game is a good assessment tool. If not, scrap it. If not, students get bored and it wastes the students' time and money. I prefer competitive games, but they don't have to be competitive to be engaging. Students can have just as much fun trying to accomplish some fun task without the stress of competition.