Website Review: http://www.edochan.com/teaching/level.htm
For students: You can play these games with your friends. Also, check out this article. It’s about learning Japanese, but there is lots of good advice for learning any language.
For teachers: The authors of these games make them fun to read about and easy to understand. You’ll enjoy games that start like this: “Have the students remove their shoes to prevent bloodshed…”
Note: This is the main site, but most of it isn’t interesting for teaching and studying English.