Guardian Force

Guardian Force is a shoot-em-up where the player controls a tank that can fire in eight directions. While the body of the tank can be moved freely around the screen, each press of the outer buttons will rotate the tank's turret 45 degrees clockwise or counter-clockwise. The tank/screen will scroll vertically for much of the game, but will sometimes be reoriented midlevel to scroll horizontally or diagonally.

There are five unique weapons which can be used: a standard shmup spread shot (Tusk), a non-continuing laser (Feeler), what is essentially a giant yo-yo that can be launched and retracted (Fang), a short-ranged explosive attack (Horn), and a bevy of missiles (Beak). Each of them has a designated color (red, yellow, green, purple, and blue respectively) and special attack (bomb equivalent), and will increase in damage/ability as the tank's level increases. The tank also has a standard repeating shot that will always fire in the direction the screen is scrolling.

Regular play revolves around a number of onscreen collectibles. The standard weapon power-up will cycle through the aforementioned weapon colors before eventually going dark, floating or fading away. It will change the player's current weapon to the one of its color when picked up, or upgrade the tank's level if it matches the color of the player's current weapon. In addition, there are pink gems that drop from particular enemies that also upgrade the tank's level, a missile power-up that will add either homing or straight-shooting rockets to the player's current weapon, and a special attack refill (equivalent to one shot).

Certain enemies and destructible objects will also drop medals when destroyed. The first medal will always spawn at level I, worth 100 points. Once it's collected, the next medal spawned will increase in rank and double in score; this continues until medals reach level VIII/12,800 points. If a medal goes uncollected for whatever reason (it either disappears or is overtaken by the scrolling screen), the next medal spawned will reset to level I. Score bonuses can also be had from quickly killing a number of midbosses, as well as collecting the weapon power-up once it stops cycling through the weapon colors.