Game help, shooting falling enemies

1

i have a game, basically missles fall from above and you have to shoot them, over all it works, but there are a few small things i can’t figure out:

  1. when you shoot an enemy you get more than one point even though it is only coded to give 1 point.

  2. when the enemies hit the ground, they are supposed to explode and subtract 1 life, but they don’t explode right away, and they subtract like 6 lives.

  3. they don’t reset fast enough after being killed

  4. you can move off of the screen

basic things like that, if anyone has time to look at it, and make suggestions, i would appriciate it greatly,

Thanks.