One of the defining characteristics of the Gradius series is the use of a "power meter." The power meter is powered by a power-up item, whose purpose, when collected, is to move a highlight to the next power-up on the power meter. When a power-up that the player wants becomes highlighted, he or she may activate it, also causing the highlight to reset.

One of the defining characteristics of the Gradius series is the use of a "power meter." The power meter is powered by a power-up item, whose purpose, when collected, is to move a highlight to the next power-up on the power meter. When a power-up that the player wants becomes highlighted, he or she may activate it, also causing the highlight to reset.