ASO II: Last Guardian (also known as Alpha Mission II) is a vertically scrolling full screen shoot 'em up released by SNK in 1991 for the Neo Geo arcade and home systems. It was later released for the Neo Geo CD in 1994 and for the PlayStation 3 in 2010.
The player controls a fighter spacecraft (Armored Scrum Object) and can shoot enemies in the air, bomb enemies on the ground, collect power-ups, and defeat bosses to advance levels.
Source: Wikipedia, "ASO II: Last Guardian", available under the CC-BY-SA License.