Invader's Revenge

Invader's Revenge definitely put several new spins on the Space Invaders formula. Rather than facing a formation of 55 invaders, there are fewer than a dozen per any given screen. Even though the invaders look exactly like the forces players faced from the original arcade game, for the most part, they do not adhere to the regular Invaders rule of moving to the side and dropping down a notch when they reach a screen edge, as the invaders mostly move diagonally. They also not only fire vertically, but diagonally as well, at times catching the player's[s'] ship in a crossfire (which is what increases the difficulty level with this game, as it is much higher than most Invaders games in general). Sometimes when an invader is shot, its body will quickly fall to the bottom of the screen and is deadly to a player's ship upon contact. The small invaders will also, after several rounds, shrink to half their width with every other move, making them harder to hit.

Players also have a fuel level to maintain, which occasionally an invader will drop down vertically to pick up a fuel cell at the bottom of the screen. If they make it back up to the top of the screen with the fuel cell, a notch of fuel will be deducted from the player's total. There are also big bombs (bigger than the ones the invaders fire) that drop from the top of the screen during levels, which will also deduct fuel if they make contact with the bottom of the screen/player's fuel supply.

After several rounds, the player must dock with the ship normally seen at the top of the screen (which the ships switch areas then, with the player's ship appearing at the top while the refueling ship appears at the bottom) to be refueled. The player must first avoid several squares in the middle of the screen, then dock with the center of the refueling ship to refuel and earn a bonus, then the game will start over at the beginning wave once more.

And unlike most other official Space Invaders games or clones, there is no UFO that appears overhead, as the refueling ship cannot be shot.

Being hit by any invader, bomb, docking square, falling fuel cell, or not landing directly in the center of the refueling ship will destroy the player's ship. The game will end when there are no more remaining ships or the player runs out of fuel. An extra ship is awarded at 1500 points.