Martin - Added mouse click button - Removed spaces - Formatted some lines

Basically I added mouse support for the aimer. Most of the lines are just formatting except these two:
menu.js
    game.input.onDown.addOnce(this.start, this);
play.js
    game.input.onDown.add(this.movePlayer, this);
Same comment as before. Have you checked if the mute button is still working (upper left button on menu)?
That's what I mean in the last comment. Every signal is caught by this event and the mute button doesn't get a chance :octocat: