This is a 1 credit clear of Fantay Zone made by Sega in 1986.
This is a bright and colorful take on Defender in the sense that the world loops over and you have a "rader" of sorts. In this game you have to destroy a base, that spawns enemies, in each sector of the level. When all have been destroyed the boss will appear.
A unique feature in this game is that it has a shop. In the shop you can purchase powerups and extra lives in exchange for coins. Coins are gathered from destroying bases, enemy formations and bosses.
Don't let the cute graphics and catchy soundtrack fool you. This game is quite brutal.