nice game
cheer up, kirby, I'm 14, and I'm not that advanced, too.
however I can make cool games with some little basics.
to learn about GE, just check out makslanes turtorials first.
there are many useful variables in there (like velocity, x, y, Z depth, transp, etc.)
once u know them, start to play around with them. most of them are controlled with numbers.
(example: when the yvelocity is 3, the actor moves down the screen with a speed of 3,
if something is rand(10), it has a random value betwéen 1 and 10,
angle can be 0-360,
and so on)
those are just basics, but once u know them, u can do pretty good stuff.
At first I copied the code, too.
but u seem to have a good start and I'm sure u'll become good programmer