I often use games during my lessons. It creates a more laid back setting. While they are focusing on the game students also tend to talk about different topics than they normally would. Playing a game together also creates a bond. New words introduced during the game are memorized five times faster than in a ‘normal’ lesson.
I meet my students at their work. They are under a lot of pressure. Playing a game may very well be the only time they aren’t feeling pressured.
Before and after they are more willing to learn hard words or to accept the corrections of their mistakes.
I only see benefits. To make the game itself interesting for their language development I never bring the same game twice in a row. So they need to use a different vocabulary every time. I collect these games, so I have quite a collection to choose from. Even so, I never have enough of them. All my students are different and over time they all have their favorite games.
I would go so far as to say that playing games is a true fundamental human need to keep our brain healthy.