Peter,
I have a couple suggestions -- (1) the HBS case series Cat Fight in the Pet Food industry can be run with teams assigned to each major firm. For each iteration, you can have the teams map out their respective strategies. (2) There are a number of experiential exercises on my teaching toolkit site -
http://research3.bus.wisc.edu/file.php/139/Toolkit/bpstools.htm. The exercise by Coff and Hatfield is excellent (Tinker Toy ice breaker), as are a number of those included in the Coff & Hatfield collection at the bottom of the page. (3) under the group break-out title there is a summary of extended session classes, and there might be some useful info in there.
Computer sims are tough because they take the students so long to get up to speed on the procedures. For most experiential exercises it is good practice to allow at least as long for the debrief as for the actual exercise, so you will want to adjust the timing with my suggestions accordingly.
Would appreciate learning about what other suggestions you receive.
Best, Mason
M. Keith Weikel Professor of Leadership
Wisconsin School of Business