History time again - Menace is the seminal first game from DMA Design, the people who went on to bring you Lemmings. It's, er, rather less original than that game, being a simple (in fact, the word 'simple' is itself almost too complicated to describe it) shoot-'em-up in the style of Nemesis and R-Type.
It's a one-way horizontal scroller with lovely graphics (a different style for each of the six levels) which at first seem to present a tough obstacle to your spaceship, until you realise that they're only there for decoration - you can fly right through everything except the top and bottom walls with no ill effect.
All that leaves to worry about is the aliens, who come at you in waves of set-pattern movements and leave behind some rudimentary power-ups when you shoot complete groups. The game's most innovative touch is having two difficulty levels, but giving you double points for tackling the second one.
Actually, level one is hard enough for most people with the one life you're provided with (unless you've got an auto-firing joystick which eases matters quite dramatically), which means that you'll get a pretty long life out of the game, assuming you don't get bored with it inside the first two hours. Which you probably will, to be honest, but there you go.