I have played this with teams and in workshops so many times that the numbers were rubbing off the dice. (The good folks at getKanban sent new sets free of charge.)
The game is played in teams of four to six people, one game per team. Each team has a playing board representing a Kanban task board, and a collection of story cards representing work to be done. Teams compete to maximise profit by optimizing the flow of work.
During the game the teams construct charts based on data from the game including a Cumulative Flow Diagram, a Run Chart, and a Lead Time Distribution Chart. Simulated events occur throughout the game to challenge the teams and require them to make various system design, prioritisation, and resource allocation decisions.
You should allow at least two and a half hours to play the game, and longer if you choose to discuss optional discussion topics during the game and/or if you wish to debrief at the end of the game. Playing getKanban with Multiple Teams Simultaneously
Games Simon Plays 
I’ve played this game … I think it’s a good intro to Kanban. I was disappointed in the columns they chose though … too waterfall. I fear that teams new to Agile may take away the wrong things from the game and end up with mini-waterfall.
Hi Dan, I agree this is a good intro to Kanban and played without an effective debrief many of the wrong take aways are possible. The power of any exercise is in the debrief.