Playing on a laptop, using the arrow keys/space bar method. I can move the cannon just fine, but I cannot shoot. I have no mouse option to try. Using Safari Version 8.0.7 (10600.7.12)

FWIW, I could shoot just fine in the boating game, obv.

The toggle for keyboard/mouse is an image of a key or mouse on the bottom right, next to the power-up meter. You can try that to switch to the mouse but I'm not sure why the space bar isn't working for you :c

I had this problem too while playing with the arrow keys/space bar method, apparently while playing that mode your mouse pointer has to be on the game screen with the ghosts flying down in order to be able to shoot the canon for some reason. It got too frustrating that way so I switched to the mouse controls. There is a picture key in the bottom right screen on the game after you've started playing, if you click it you can use mouse controls. It took me a while to figure that out because the instructions weren't clear about how to switch the controls.

I was in fact on the key, but I figured out the problem. I simply clicked in the ocean, and then it registered that I was playing the game. Perhaps it was that the pointer was "in the game field". Hopefully other people can see this and be saved the frustration!

Thank you both!

Oh, yeah I forgot about that. I wanted to keep my mouse over on the side with all the controls and stuff but I had to keep it on the boat :L

I am having the same problem, I'll check if your solution works for me too.

Edit: It works! Does not improve my playing skill though :P