Bullet
From YoYoGames Wiki
To create a bullet, follow these steps:
1. Create a sprite, preferably a small ball
2. Create an object and attach the sprite to it
3. Add a collision event with any object you want it to perform actions on, and do things to, such as lowering health, destroying the object (remember all the actions must be marked "other" unless you want it to affect the bullet or another object other than the one that was by hit the bullet)
4. Create an object that spawns bullets, use create moving instance (direction 90 is up 270 is down 0 is right 180 is left)

