When Boomerang woman is hit she will be knocked back in the opposite direction of which she is facing no matter where she gets hit from you can use this to boost through enemies since while this animation plays you have iframes which last for a while long after the knockback is over

The boomerang's hitbox is large which allows you to hit enemies without having to jump if the platform the are on is low

When enemies are hit you have a few frames during which they won't be able to damage you which allows you to walk through them this is useful for bosses that have a charge attack such as the Boss on level 4 and level 5