Explaining the game took around 5 minutes. I demonstrated some movies and showed them (via the game's box) how words can be stacked and connected. The kids seemed to understand.
Seemed is the key word because in every class, there was one group that didn't get anything about how to play them game. They acted as though they never heard or saw my instructions. And despite having the instructions for the game in Korean, each arrant group paid them no mind. I stepped in to redirect and reteach as often as possible to no avail as well. After a while, I gave up and let them build letter towers, cover the board in alphabetical order, or make every disconnected word they could think of. I saw that they chose to ignore the rules of the game. I thought about punishing them, but figured it best to let them be. They were occupied and using English. Some battles are better left unfought.*
Oh well. One group out of three or four isn't bad. The rest of the kids caught on and had fun playing UpWords. Many didn't bother keeping score, a fact I found interesting because of how competitive the students can act. The kids knew how to keep score, but they didn't. I'll return to the game in the future, for it's good for building vocabulary. It'll go better next semester.
Update (17 July): Participation hit 100% in the last couple of classes!
*It's the end of the semester and many students have lost the will to do anything other than sleep or moan. Most get going when everyone else gets going though.