Feature rounds are the most demanding part of a game for a device to render. Particle effects, layered animations, and full-screen transitions run continuously during a purchased round, whereas ordinary spins spend most of their time idle between short bursts, so a session consisting only of features drains a phone battery and consumes data noticeably faster. Anyone playing straight to bonus slot games on mobile for an extended period may want to lower the graphics quality in the settings menu, where the option exists. Older handsets can also overheat.