Algodoo

You forgot to declare the variables... at least Scene.my.power. It doesn't work as it is now. Also, on the fuel's timeToLive, you used e.geom. to refer to the fuel itself, and you used colons. That is wrong, colons are only used when you define the variable for the first time, i.e. when you spawn the fuel. After you spawn the fuel you don't have to use them, or you'll have a myriad of errors. Try making the engine work and opening the console...
Also another thing, e.pos is crap, it always gives back the position of the event but one step late. this makes stuff spawn outside of where you want it to spawn. Always use pos or e.other.pos whenever you can, those two work
This would be the corrected code, with some tweaks from myself (didn't change e.pos though, you'll have to see what to do since it doesn't work well with pos):

(e)=>{
scene.addCircle({
radius := 0.0125;
density := 0.01;
restitution := 0;
friction := 0.0;
refractiveIndex := 1.5;
pos := e.pos;
colorHSVA := [90.0, 0.56, 1.0, 0.3];
drawCake := false;
vel := entity.vel;
timetolive := 2;
heteroCollide := false;
collideSet := 5;
zDepth := 100;
onHitByLaser := (e)=>{
e.geom.density = {
scene.my.power * 200
};
e.geom.timetolive = 0.01;
e.geom.collideSet = 3;
e.geom.radius = {
scene.my.power
};
e.geom.friction = 0;
e.geom.colorHSVA = [25.0, 1.0, 1.0, 0.5];
e.geom.onDie = (e)=>{
scene.addCircle({
radius := 0.025;
density := 0.001;
restitution := 0;
friction := 0.0;
refractiveIndex := 1.5;
pos := e.this.pos;
colorHSVA := [0.0, 0.0, 0.0, 10];
edgeBlur := 0.5;
drawCake := false;
vel := entity.vel;
timetolive := 5;
heteroCollide := false;
collideSet := 9;
zDepth := 100;
friction := 0;
airFrictionMult := 1
})
}
}
})
}

One more thing: you're welcome to upload any scenes you want to our alternative site, algo.boards.net. You don't even need to upload the scene, you can get the scene ID here (it's in the url: 160696) and use it there to get a direct download link

It's not really operative yet since we're like 5 guys there, but the idea is for us to upload our meaningful scenes and get people to see them whenever they get there. Like a Popular scenes page but with our best scenes.

Thanks for the input, I'll try to remake it and fix the code. I'm a terrible scripter, in fact this fuel code was copy and pasted and I've just tweaked some of the variables.