No matter if they are Flash games or applications, I was never sucessfull to make them work within Resolume.
But, if you mean a full screen usage and no mixing with Resolume content at all, there´s a simple solution:
I run all my flash games and applications in my mac / pc side, while running Parallels.
I move the Flash player window to the 2nd monitor output position (>>>>> to the right) and then "CTRL + F" to make it full screen.
Then it is just like multitasking windows - but for the output ; ) Whenever you select your flash player (option +tab on Mac I guess) for active application, Resolume output will be overlayed by your flash game content.
Humm... that makes me wonder... is Parallels Syphon friendly??