Hi im not the person who designed the Pixel Art Asset Pack but i am a person who has helped people work on projects before.
Range attacks are made up of 3 factors
1. The sprite
2. The code
3. The Sprite that is using the ranged attack
When making a range attack sprite you want its color to be not the same as the background. This why SNK liked using Yellow for there shots.
basically your image should be able to fit in one tile worth.
Make sure to say what the bullet looks like, once ya got that down heres the rest.
If you want some motion or animation on it make it around 5-7 frames
It really depends on how long your bullet is going to be active.
If you give it too many frames or too little frames it will repeat the animation multiple times.
When the bullet is created give it a direction and a speed and whatever damage variable your game uses for damage.
Give it a timer where it strait up unalives itself so it doesnt take up excess data
Have it destroy itself after it applies damage and when it hits something
This is for a basic bullet if you want more than this then i recomend looking up something or experimenting after you figured out these basics.
Oh and make sure your bullet is created from the place you want it to be when you fire.
Otherwise in most engines you will get a visual error its not a coding error but basically it will have bullets created from the torso instead of the gun.
Theres more to it than just this but this is enough i feel you get you started sorry im over 90 days late but i just noticed your comment.