The Day II

The android terrorist organization Metalabor stole the highly valuable Mega
Plutonium K element, intending to use it for military purposes. Their biggest
mistake, however, was kidnapping the sister of the pilot Captain Lee in order
to force their father, a famous scientist, to aid them in their nefarious
plans. Captain Lee decides to rescue his sister alone, and perhaps find a way
to stop Metalabor altogether.

The Day II is a horizontally scrolling shoot-em-up and (notwithstanding its
title) the first entry in the Korean-made series. The player controls a
different spaceship in every mission, though they play nearly identically
(with the exception of the range of the smart bombs). Different weapons and
power-ups (such as a life-adding item) can be collected throughout the stages.
Each mission ends with a boss battle. The game features three selectable
difficulty levels.