Three Unknown Items are found in Metroid: Zero Mission. All unknown items were found in Chozo Statues different from the other ones Samus finds in the game, as their structures seem to have greatly aged (and are starting to break down) with time and are more avian-looking. Unlike the other upgrades in the game, unknown items have a dull grey colour and do not glow; like the statues, they appear to be very old. Initially, they are unusable by Samus Aran as upgrades, but allow her to destroy certain blocks bearing images of the associated Unknown Item. Until the player defeats the Chozo Hieroglyphic late in the game, the Unknown Items appear as garbled, mixed up text of an unknown language on the inventory screen. After defeating the Chozo Hieroglyphic, the Unknown Items' true identities are revealed to be the Gravity Suit, Plasma Beam, and Space Jump. A Japanese interview stated that they work because the Power Suit that Samus gains here is a "legendary one", and therefore compatible with older technologies.
Zero Mission Samus Screen dataEdit
"Analysis inconclusive. Item incompatible with current suit."
- The Unknown Items are all items not available in the original Metroid game, and coincidentally resemble the Sacred Treasures from Kid Icarus, which used the Metroid engine: the Mirror Shield (Gravity Suit), Light Arrows (Plasma Beam), and Wings of Pegasus (Space Jump). All three were required to go to the last level of the game, and were not usable before that point.
- In Metroid: Other M, scanning the Diffusion Beam or Seeker Missile brings up the message "Details Unknown", similar to the Unknown Items. Details Unknown is also used as the description for Madeline and Melissa Bergman when they are recorded as "Identity Unknown".
- Metroid Prime 2: Echoes also contains an unknown item, but once collected is revealed by U-Mos a short time later to be the Energy Transfer Module.