I have just come back from Siggraph, where they presented a bubble making machine, which gave me an awesome (?) idea how to take your system to the next level:
Instead of having virtual bubbles on a screen to pop, have _real_ bubbles:
a bubble making machines makes bubbles, out of soap, that has a little bit of fluorescent ink in it, which you can buy as ink for safety markings etc. Then there is a camera with a filter that detects the bubbles and tracks them, as they come out nicely in the camera when illuminated with IR or black light, so nobody can see! And when you pop the bubbles, a loud sound is played! The higher the bubbles are in the air, the higher the player has to jump, the more points you get.
Also, I found this company that might be interesting to you: