幻想空间

In the game, the player's ship is placed in a level with a number of bases to destroy. When all the bases are gone, the stage boss appears, who must be defeated in order to move on to the next stage. There are eight stages, and in all of them, except the final one, the scrolling camera is not fixed; the player can move either left or right, although the stage loops. The final level consists of a rematch against all of the previous bosses in succession before facing the final boss. Opa-Opa uses two different attacks: the standard weapon (initially bullets) and bombs. He can also move down to land on the ground by sprouting feet and walking around until he flies again. It is possible to upgrade Opa-Opa's weapons, get bombs and flying engine to increase speed, and get extra lives. To do these, the player must get money by defeating enemies, bases or bosses, and access a shop by touching a marked balloon. Prices rise with each purchase. When the player chooses to exit or the time runs up, another screen appears to equip these upgrades; only one engine, weapon and bomb can be equipped at a time. Some of the purchasable weapons have a time limit that starts as soon as the shop is left. Some of the bombs can be used at any moment, but are limited in quantity. Engine upgrades are permanent. The powerups can also be reassigned by reentering the shop or touch a balloon with the word "Select" written on it. If the player loses a life, all of the upgrades are lost.