Doesn't the post above yours answer your question?
You can shoot the other player from below?
Mine has not arrived yet.
How do you open the CX80 Trak-Ball?
If screws are under the rubber, is it sticky enough to replace and stay put without cleaning and new adhesive?
I hate when one or more rubber feet are missing on trackballs and Starplex controllers because they work best for me on a table surface. Things I hold like joysticks I don't care so much about the feet.
I don't have a second trakball to test. I noticed there's a two player coop and two player competitive. What's the difference between these options?
Almost reminds me of Joust and Balloon Fight where you can work together or try to annihilate each other. If both players are simply holding the fire button, you'd be hard pressed to swap sides without crossing the line of fire unless you're both riding the rail.