What a gem! I never played the original but this is a fantastic game and concept - thank you for bringing it to the PD.
Couple of things... first, why does the tripod say 3210? Second, could you allow the B button to also fire (it is more comfortable in my hands this way)? And finally, I noticed some strangeness when you fire parallel to the bottom of the screen... the ball will come to a stop below the line and allow you to continue playing. You can also shoot balls into other balls this way. Not a big deal but just seemed unintended.
Thanks again & especially for the source as well, very helpful learning tool.