Missile Expansions increase your maximum missile capacity by 5. There are numerous Missile Expansions throughout Aether, and collecting them all is essential for having enough firepower to defeat bosses and open missile-locked doors. A full missile capacity makes many encounters significantly easier, especially when dealing with enemies vulnerable to missiles or when using the Seeker Missile.
Similar to Energy Tanks, Missile Expansions are often hidden behind environmental puzzles, require specific beam types (Light or Dark Beam) to activate switches, or are located in areas accessible only with Morph Ball upgrades like the Boost Ball or Spider Ball. Some are found in plain sight but require careful platforming, while others are tucked away in obscure corners of the map. Regularly check your map for unexplored sections and use your Scan Visor to reveal hidden pathways or weak points in walls.