XOR (video game)
XOR is a puzzle video game created by Astral Software and published by Logotron in 1987 for the Acorn Electron, Amiga, Amstrad CPC, Atari ST, BBC Micro, Commodore 64, and ZX Spectrum.
Gameplay
Objective
The player controls two shields, Magus and Questor, which can be moved horizontally and vertically though the maze, in order to collect masks. The object of each level is to collect all the masks, then reach the exit. In all levels, use of both shields are required for completion, and in some, one shield must be sacrificed in order to complete the level.Force fields
In the first level, the only obstacles except for the maze walls themselves, are two types of force field: one of which can only be entered from above or below, and a second which can only be entered from left or right. In both cases entering the force field destroys it.Fish and chickens
In subsequent levels, fish and chicken objects are introduced. Fish fall downwards whenever possible, while chickens run to the left if not blocked. Both can destroy the player's shields by hitting them from more than one square away. Fish and chickens can move through force fields if entering from the appropriate direction. It is also possible to push fish left or right, and chickens up and down.Bombs
There are two types of bombs in XOR: "V-bombs" and "H-bombs". V-bombs move left in the same manner as chickens, while H-bombs fall downwards like fish. Like fish and chickens, H-bombs can be pushed left and right, and V-bombs can be pushed up or down, by the player's shield.A bomb explodes when it is hit from more than one square away by a fish, a chicken, or another bomb. The object hitting the bomb is destroyed, along with anything directly above or below a V-bomb, or to the left or to the right of an H-bomb. If one bomb hits another, only the bomb that is hit actually detonates.