Video games in the 80s only depicted a certain amount of pixels on the screen. Fortunately, that didn't hold developers back from pushing the limits of the available hardware to play with our imagination by creating beautiful, handsome characters.
Like any other artistic medium, most video games "borrow" content and ideas from other titles. That's how inspiration works. There's a line between inspiration and copyright infringement, though, and in 1987 Time Warp Productions jumped over that line (then into a warp pipe).