It saddens me to hear this. I use Scientific Linux and love yum. Thank you for your hard work, but you are in a better place now. You will be missed.
As a SL desktop user, I hope this doesn't negatively affect SL. But, I hope Troy and Red Hat do well together.
You may be interested in some of the games from the Virtual Immersive Technologies and Arts for Learning Lab (http://vital.cs.ohiou.edu/). Under software, you may find some games that would appeal to your class. I used to be involved in the VITAL Lab and found that the flash games worked best in classrooms. As far as I know, the program is no longer active (ran out of funding), but the resources are still available online for anyone to use.