Halloween is almost upon us. Though many of us are too old to go trick or treating, we're definitely not too old to be scared stiff. There is however a good chance that you've exhausted many of the newer horror games released in recent years.

So what do you do? Turn to the scariest titles of yesteryear, that's what. All of these titles can be played on modern hardware using the right tools and tweaks — so turn off the lights and prepare for a (somewhat pixelated) fright.

Doom 1, 2 and Final Doom

When I was four, my parents brought home our first ever Windows computer. It was massive - a Packard Bell that weighed as much as a child, and came with a humongous 15" CRT monitor. At the time, manufacturers often bundled their computers with free, premium software that would otherwise cost a lot of money.

This was twenty years ago. My memories are pretty hazy, but I recall it came with Ecco The Dolphin, and Corel Draw. I also remember it shipped with a copy of Doom on CD-ROM.

Although primitive by today's standards, Doom left a massive impression on me. It was the first FPS I'd ever played, and it's the one I remember most. Two decades on, I can still remember the cheat codes for it - IDDQD for God mode, IDKFA for all weapons.

But above all, I remember feeling absolutely petrified playing it. Doom really made you feel helpless and alone. It was brutal, and unflinching, and despite the blocky, pixelated graphics, it felt real at the time.

ID Software open-sourced Doom a while back. As a consequence, there are now a number of free, Doom-like clones on nearly every platform, including Android and iOS.

The original game files, however, were not open sourced. You'll either have to own an original disk, or play someone else's home-brewed levels with the aid of the Freedoom project. Failing that, Doom 2 and Final Doom can be bought on GOG for $9.99. The Ultimate Doom, which bundles the first episode plus four extra levels, can be had for $5.99. Although only available for Windows, they play perfectly on Linux and Mac with Wine.

Last Half of Darkness

Back in 1989, the ability for a computer to create suspense and fear through music and art was limited by the relatively unsophisticated hardware of the time. Developers had to be creative, and focus on narrative and suspense.

Take Last Half of Darkness, for example. Originally a DOS game, LHOD places you in a haunted mansion, set in the swamps of Southern Louisiana. Graphics are two-dimensional, and eight-bit. Music is very a la chiptune. But it still manages to unsettle, thanks to its well written storyline, and vivid textual imagery.

Last Half of Darkness is abandonware, and you can play it online, in DOSBox

You can play Last Heart of Darkness in the browser, on DOSBox (explained here), or Boxer (a Mac-friendly take on DOSBox) for free, thanks to its abandonware status.

Alone In The Dark 1, 2, and 3

Released in 1992, 1993 and 1994 respectively, the first three episodes in the Alone In The Dark series set the standard for horror games for a long time. Each one expertly blended a cocktail of fear, action and storyline, and remains eminently playable today.

In each game (apart from the third, which featured an optional female protagonist) you play Edward Carnby - a down-on-his luck private detective, living in 1920's America. Unlike many of the games on this list, Alone In The Dark feels lighter. There's an element of slapstick in its horror. It's more Adams Family, and less The Exorcist. And that's not a bad thing.

You can download the first three episodes of Alone in the Dark from GOG for only $5.99.

I Have No Mouth, and I Must Scream

Even the name of this game unsettles. Released in 1995, it was based on a short story of the same names published in 1967, by sci-fi wunderkind Harlan Elison.

I Have No Mouth, and I Must Scream depicts a nightmarish vision of the future. In it, humanity has been almost annihilated by the Allied Mastercomputer (AM, for short) — a sentient machine, with a burning hatred for humanity. Just think Skynet, but even more misanthropic.

But the Allied Mastercomputer has saved five unfortunate people (four men, and one woman), each with a hidden and sordid past, who he has confined to a prison in the center of the earth. Their lives have been artificially extended, merely so that the machine can torture them indefinitely.

After 109 years of his torment, AM announces that he wishes to play a game. It's up to each of the protagonists to delve into their past and uncover their last, deepest, darkest secrets; to defend themselves against AM's psychological warfare, and to eventually free themselves from the clutches of the psychotic machine.

I Have No Mouth, and I Must Scream isn't for everyone. It's dark. As dark as any game I've ever played. It's certainly not suitable for children.

You can purchase it from GOG for $5.99, or from Steam for the same price. You can also play it through the SCUMMVM if you have the original game files.

Phantasmagoria

Much like I Have No Mouth, and I Must Scream, Phantasmagoria was a dark and controversial affair. So much so, it was banned in Australia, and the recently-defunct big box retailer CompUSA refused to stock it.

That was mostly due to its adult themes, and the fact that it didn't shy away from gratuitous violence. This isn't for kids or for sensitive players.

What makes it one of the most unusual items on this list is that it was an interactive movie (a genre which is having a rebirth at the moment). The game consists of live-action video, rather than computer-rendered graphics. This gives it an added veneer of realism, and makes it all the more engaging.

Phantasmagoria tells the (highly unoriginal) story of a young girl, trapped in a haunted mansion. What sets it apart is the way it feels like a big-budget, cinematic production — in a way that was truly rare for a game of that era.

You can download it on GOG for $9.99. The sequel, which was less well received, can also bebought for $5.99. Although it is only available for Windows, it works perfectly on Wine on both Mac and Linux.

System Shock 2

I know I'm bending the definition of "retro" a little bit, but I simply can't conclude this article without at least fleetingly mentioning the 1999 first-person fright-fest System Shock 2.

The game takes place in 2114, on a derelict starship that's been overrun by a genetic infection that has transformed humans into violent, murderous mutants. So far, it doesn't sound particularly unique, or for that matter terrifying.

But System Shock 2 was more than just a mindless shooter. It knew how music and lighting could create suspense, and in turn, fear. It had a story that engaged, and unlike most of the games of the time, it had fairly decent voice acting.

Fifteen years after its release, it remains the most frightening game I've ever played. It's something I can only really bear to play with the lights turned on, and with my headphones unplugged.

System Shock 2 is available to download from GOG for $9.99, if you dare.

Don't Have Nightmares

If you've finished SOMA, Amnesia and Until Dawn and wish you'd saved something for Halloween, these titles should get the blood pumping, whether you played them first time round or not.

But you've probably got your own favourite retro horror games — and I want to hear about them. What golden oldies will you be revisiting this year?