Hi all, I'm interested in creating a very common game element - an explosion.

What I would like to get some feedback on is:

The size of the explosion
For how long it should last
at what distance from the explosion should things start to fade out?

Bit unclear? Stay with me, I'll use an example:

let's say that an explosion occures at these pixels:

x: 200
y: 250

The size of the explosion (the radius) is 20 pixels.

if we follow a particle that travels from x: 200 to the right (along the x axis) then how fast should it travel?

Also, it would make sense to me if the particle fades out, but when should it start to fade out? how rapidly should it fade out?

Looking forward to your feedback as I am not that experienced in classic animation techniques.