+New Weapon +Mini Bosses + All the items + other stuff.

+New Weapon: So there are forward flying rockets and homing rockets
(provided you can place the cross hair on top of some enemy).

+Mini Bosses: This are just smaller (literally) bosses, that try to
crash on you, and have some unique weapons, plus they come in groups.

+There are now items for all the weapons, a "power up current weapon"
item, a speed item, a health item and a 1-UP item.

+Assorted bug fixing and some clever solutions to avoid duplicating
code. Namely in PowerUp.js and Rocket.js