The following details are from the English Acceleration of Suguri X-Edition webpage:

After catastrophic events on Earth, an android named SUGURI was created to protect Earth from an impending invasion. The original SUGURI is a side scrolling shooter, and the sequel – Acceleration of SUGURI – has all of the bosses from the first game in the form of an aerial-style shooter – flying, dodging, and frantic shooting in the form of an exciting fighter, and even a Player versus Player mode!