Fully charge your Charge Beam to do a Screw Attack.
At the end of most Metroid games, you get an iconic move called the Screw Attack that pretty much renders Samus invincible to physical contact from regular enemies, and it's a one-hit kill. However, there is a way to do a significantly weaker version with the Charge Beam. If you do a spin jump while your beam is fully charged, your flip will damage enemies, killing many in one contact.