that is just because once the energy = 0, the life is lost
BUT you need to set energy = 100 for the new life!
or the counter will keep loosing lives if energy = 0,
so it will go: lives 3 -1, 2 -1, 1 -1, 0, and you will only see 3 -> 0
where it says "if the life counter is ON, lose 1 life, turn life counter OFF"
add: *set global variable 'energy' to 100*
but then what happens is, you lose a life,
the counter shows 2, and energy 100, but no plane!
because you destroyed the plane a forgot to create it again!
you can either spawn a new plane at XY, or just move it XY and not destroy it.