Walker is a computer game released for the Amiga system in 1993, where the player controls a huge ED-209/mecha styled device fight against military forces in various time periods.
The walker travels through time and space to 1944 Germany, 2019 Los Angeles, present-day Middle East ("Tonight"), and an unknown place in the distant future. There are two difficulty levels in the game: easy and arcade. Only the first two levels are playable on easy mode; the game will end after completing the second level, displaying a message to the player to try the much harder arcade mode. Much of the opponents are huge waves of small weak infantry, comparable to DMA Designs's Lemmings in that they are very small but individually animated with great detail. For example, infantry will splatter into a pool of blood when shot at.
Walker featured a novel control system for the time in which the player simultaneously uses both the mouse for aiming at targets on the screen and firing, and a joystick or keyboard for movement of the Walker. Thus two people could even be used to advance through the game's tougher sequences. The player also has the ability to lock onto enemies by moving the crosshairs close enough to the target and clicking and holding the right mouse button. Another feature of the game is that the guns of the Walker overheat if they are left on firing too long. For this reason, the player cannot fire continuously for more than about six seconds before having to rest the guns for a couple of seconds.
The player moves from right to left, rather than left to right, which is unusual for a game of Walker's type.
Source: Wikipedia, "Walker (video game)", available under the CC-BY-SA License.