Item Boxes, also known as Monitors, are destructible containers scattered throughout each act. Breaking them open (usually by running into them or using an attack) reveals a power-up. There are several types of monitors, each providing a different benefit:
- Ring Monitor: Grants you 10 rings instantly. Always useful for boosting your ring count or recovering after taking damage.
- Speed Shoes Monitor: Temporarily increases your movement speed beyond your normal top speed. This is excellent for clearing long straightaways or difficult sections quickly.
- Invincibility Monitor: Grants temporary invincibility, making you immune to all damage from enemies and most environmental hazards (though bottomless pits and crushing walls still defeat you). Use this to power through dangerous areas.
- 1-Up Monitor: Grants an extra life. These are often hidden in secret areas or at the end of challenging optional paths. Always worth seeking out.
- Shield Monitor: Provides a temporary shield that protects you from one hit of damage. Unlike rings, the shield absorbs the hit without scattering your rings.
Knowing the location of these monitors and utilizing their effects strategically can greatly improve your performance in each act.