Particle Effects Vs Illustration Advice

As one of my first projects in unity I aim to design a sort of "gun simulator game", first creating a laser weapon using pixel art just as a demo to see what I can produce. I'd like to have the weapon "charge up" by having some semi-transparent red pixels emanate from the barrel of the weapon.

My question is, is this the sort of thing you should be animating when creating your artwork (e.g. within the sprite sheet originally) or should you be using particle effects? Considering development of the game in the future, in which I may implement some sort of recoil, would it be better to make use of unity's rotation for that (smoother?) or physically animate this within the sprites? If the game were to develop further, which of the two approaches would be better in terms of pc running performance? Is there another better approach that I have not discovered yet?

Apologies if I haven't made myself very clear, as I said I'm extremely new to this and would appreciate any feedback!