Wow this is much cleaner and it works perfectly, thank you greatly.
Now I'm interested in a few explanations:
1)What's the advantage of using booleans here?
2)Is there a way to place correctly and easily the origin points? (shoot_fx) for example. I had to place this one blindly...
3)In the "shooting" section, you used the function "spawn sprite on layer 0 (image point 1), I need an explanation for this :)
Really sorry again about flooding with questions, but despite me looking at the manual, many informations don't look naturally obvious to me. I have no experience in game making, this doesn't help.