The Guardian Legend/Items

Item tiles
Throughout the game, you must collect various items to improve the firepower and health of the Guardian. Items may be found inside capsules like the one shown to the right. You must shoot the capsule to obtain whatever item it contains.

Keys
Doorways that have symbols in them require the key with the same symbol in order to access what's found on the other side. Keys are not obtained from item capsules like the items described above. They are obtained by defeating the bosses found at the end of particular corridors. Find these corridors and defeat the bosses found at the end to obtain the keys which will expand the amount of labyrinth that the Guardian can explore.