Gun Nac Nintendo

Players fly their ship up the screen across various landscapes and shoot at enemies who descend from the top of the screen. Players have guns and bombs at their disposal to destroy enemies. Guns have unlimited ammunition, and are a player's primary form of attack. Bombs are more powerful, and are used up through use. A player begins the game with three lives. If the player makes contact with an enemy or an enemy projectile, they will lose a life and restart without the powerups they had collected to that point.

Much of the strategy in Gun-Nac emerges from collecting powerups, of which there are several. Powerups are released when enemies are destroyed. There are five types of guns in the game and four types of bombs. These are represented visually as circles around numbers (for guns) or letters (for bombs). By collecting identical weapon powerups in sequence, a player can enhance that weapon's capability. For example, in it's basic form, the starting gun (number "1") simply fires directly ahead of the player. If the player collects more "1" powerups in sequence, however, the gun will start to fire forward, to the sides, and even behind the player. The maximum power of a weapon is reached once five of its powerups have been collected. If a player collects a weapon powerup that is different from the weapon they are currently using, they will immediately switch to the new weapon at it's lowest strength. This means that a player must avoid unwanted powerups in addition to enemies.

Additionally, enemies will sometimes drop a "wing" powerup. This adds improves the capabilities of whatever weapon the player is using and allows the player's ship to endure one extra hit before the player loses a life.