- "What's big and slow and moves like a floaty bat? A bad bubble of course."
- ―Downwell instruction booklet
Bad bubbles behave similarly to a bat, attempting to hit the player by homing on to them. However, they are not fast nor agile - it takes a little while for them to accelerate in order to move around. Bad Bubbles additionally bounce off of objects, and are incapable of pathfinding around walls or floors.
Bad bubbles are easy to handle, only taking three bullets to dispatch. Their large area and slow movement makes them easy to stomp on. As a starting enemy, their intention is to orient the player on the nature of of the game and other enemy behavior. As a result, they posses no special abilities or gimmicks.