The generosity of hitbox detection is a known rule in game design, don't worry, you'll learn all those small details as you make more games. Here's a video explaining it (also check out the videos of that channel, they're very useful)
Hey, remember that the collision boxes were too big? I found out that when I was resizing the sprites I only changed the HitBox that gets recognized by bullets and walls, not the one that hits the player, only took me 2 weeks to find out LOL
