creating a jump attack

the turtle can attack and mid air attack with a different move like in most platformers
please let me know if there's a better way of doing this? as I'm having issues as sometimes the launching animation is still displaying, any help welcomed please? :( only wanted to recreate my childhood obsession with the nes game

the controls are (keyboard)

space: to start on title screen
arrow keys: left & right
shift: jumps
Z: attack
jump and then Z: jump attack