Source: Wikipedia, "Giga Wing", available under the CC-BY-SA License.
Giga Wing is a 1999 vertically scrolling shooter arcade game developed by Takumi and published by Capcom on their CPS-2 arcade system board and ported later that year to the Dreamcast console. The arcade version is notable for using a horizontally aligned monitor (much like Treasure Co. Ltd's Radiant Silvergun), something that is considered rare for a vertical shooter.
Giga Wing takes place during a fictional war within a steampunk setting. The player controls one of four different futuristic aircraft and must destroy enemy aircraft, tanks, ships, and buildings using both guns and missiles mounted on the aircraft and a limited supply of bombs which damage or destroy all enemies on-screen when used. The game is based on the player(s) trying to destroy a medallion which possesses great power. Many of the bosses use the medallion as a weapon. At the end, it shows that an evil man who pilots a ship called the "Stranger" is the real person who is in control of the Medallion, and was responsible for the war, as well as other conflicts in the past including World War 2, and you fight him three times as a mini-boss and as the last boss. He appears to be a friend of Stuck 30 years ago when you fight him with Stuck.
There are four different characters in the game, and each of them has their own individual storyline. Players can also do team play mode that has two characters at once, creating a new storyline. In each storyline, there are two endings. In the bad ending, the character the player uses will sacrifice their life in a kamikaze attack that destroys the Medallion. In team up mode, generally one of the character does this, but in sometimes both characters survive. In the good endings for either solo or team play, the characters don't sacrifice themselves.
The player chooses one of four different craft and shoots through seven stages. Each game (on default settings) begins with three lives, and an extend can be earned in stage four if specific requirements are met. The option to continue is given when all lives are lost, although the seventh stage is only accessible if the player does not use any continues.