Appearance: Red, glowing cubes or geometric shapes.
Function: Collecting an Overdrive item replenishes one stock of your 'Overdrive' special attack. You can hold a limited number of Overdrive stocks (typically 3-5, depending on the difficulty and Area). Overdrive is a powerful screen-clearing attack that destroys all on-screen enemies and grants temporary invincibility. It's an invaluable tool for escaping overwhelming situations, clearing dense projectile barrages, or quickly dispatching high-HP enemies. Strategic use of Overdrive is a hallmark of skilled play. Don't hoard them indefinitely, but also don't waste them on single, easily defeated enemies. The sound effect for collecting an Overdrive item is a distinct, deep 'thump'.