Here's how I experienced the game:
- At first I thought that you should be able to move the cannon left and right.
- My second impression was that it must have been a conscious decision to keep it simple like this, and it actually works nicely like that.
- My third thought, as I was beaten by the enemies, was that I'd still prefer being able to control the cannon, and shoot them in the order I want.
- But then I actually read the instructions and noticed that you can click the extra zombies for extra points. :) That's a nice addition to the gameplay and a good justification for the simpler cannon controls.
Some kind of a combo system might be a welcome addition to the gameplay, but it's a nice little game, with a well-suited choice of music!