I owned this electronic board game at one time Dark Tower, a classic Milton Bradley release of the early 1980′s. A true collectors item, working editions can still be found traded on E-Bay.
Lucky for you, in the Internet Age you can just click over to Hot Flash Games to play a flash port of it. However, you are out of luck on multi-player – the Flash version is single player only.
It was quite an ingenious game for its day and although it is very primitive by modern standards it still has its fans.
As it turns out, there is also an interesting trade secrets case surrounding the game. For some reading on that subject try Triumph: the Origin of Dark Tower. Also of interest, Board Game Geek has a good page on Dark Tower.