Life Energy

Life Energy (ライフエネルギー) is an item in the Mega Man franchise. When touched, the item will recover a set amount of life energy from the player's character. They are usually found as an item dropped by defeated enemies, but can also be found in stages and by other methods, such as being possible rewards from the ? Can and Eddie. Except for the ones found in stages, Life Energy items will disappear a short while after its appearance on the screen.

The original Life Energy shows up during a side quest in Mega Man ZX Advent, being called a "Light Bulb," likely as a reference to the original Mega Man being solar powered.

Recovery
Life Energy usually comes in two sizes, small (小) and large (大), but some games contain extra large (特大)/MAX versions that usually completely restores health. The small ones traditionally replenish between 2-4 units of the player's health, while the big ones restore between 8-10 units. In Mega Man 7, an extra large Life Energy can be found in Spring Man's stage using Rush Search (in the area with a lighter star in the background). This giant Life Energy only appears in this stage and has made no later appearances in the original series. In the Mega Man ZX series, the large Life Energy items can be sliced with saber weapons to create smaller and different types of energy items (Weapon Energy and Energy Crystals).

Life Soul
Life Soul is a variation of the Soul Item from Mega Man Xtreme 2. It has the same effect of the normal Life Energy when collected, but also acts as currency to obtain Parts.

Energy Cube
Energy Cube (エネルギーキューブ), also known as Recovery Cube, is a red cube from the Mega Man Legends series that acts like the Life Energy item, being dropped by enemies and recovering health when touched.

Trivia

 * While the Life and Weapon Energy items gained a new appearance in Mega Man 2, the game's North American manual uses the same pictures from the first game.