I have a confession to make. I never played Serious Sam back in the day. That's right. One hell of a noob, me.

I knew all about it, of course. I knew about the gore, the one liners, the barmy enemies, the huge bosses, the big weapons, the time travelling, the ancient Egypt setting - all of it I'd heard about. Now though, over eight years after it was originally released on PC, I can happily proclaim that I have played Serious Sam. Well, a high definition remake at least.

It counts, though, because bar the complete "built from the ground up in HD with trillions of polygons using the Serious Engine 3" approach Croatian developer Croteam has taken with Serious Sam HD, it's the same game: same rooms, same puzzles, same enemies, same Serious Sam. If you're like me and missed out back in the day, the game affords a welcome opportunity to see what all the fuss is about.

So, what is all the fuss about? Having played a preview build of the PC version, I can safely say that Serous Sam HD is an old school PC FPS, and that's just the way it should be. It's fast in a way that modern day first-person shooters aren't, but don't let that put you off. Serious Sam HD, from what I've played, is serious fun. No nonsense, no brain cells required fun. It's about having a quick trigger finger and a twitchy wrist. You can pick SSHD up and play it, just shooting the hordes of monstrous enemies in the face and pushing switches here and there to solve simple puzzles until you complete the game. Or at least, that's the way things are on the easier difficulties. A challenge is there if you want it, but if you don't, SSHD isn't so old school that it'll punch you in the face then add insult to injury by kicking you in the gut while you're down.

To give you an idea of just how barmy Serious Sam is, here's the premise: you play muscle-bound nutjob Sam "Serious" Stone, who travels back through time to ancient Egypt to kill the forces of the alien overlord Notorious Mental. That's right. The baddy is called Notorious Mental.

You hear them coming. Then they blow up in your face.

It's all just an elaborate excuse to shoot demons in the face of course, and oh my, what demons SSHD has. Here's a list of a few of the enemy types I encountered during my play through of the opening Thebes level: Headless Kamikaze (no heads, bombs for hands, charge at you screaming); Sirian Werebulls (take ages to kill but can be coerced into smashing down previously impassable doors); guys with buzz saws for heads; creatures that look like they should be on the front of a packet of Monster Munch; little bastard frog things; screeching, flying harpies; skeleton horses that charge at you from every direction; and huge robot walkers.

While the majority of the enemies you go up against are sensibly sized, some are not. In the Valley of the Kings level I went up against an Ugh-Zan: an enormous boss reminiscent of the four-armed demon Goro from Mortal Kombat. It was a quite spectacular sight - its new fangled graphical fidelity and its sheer size almost bowling me over.

The gore and over-the-top violence remains intact

Sounds like suicide, doesn't it? Well Sam, as you'd expect, isn't defenceless. In fact, he's got an arsenal of which Arnie would be proud. He begins with a pistol, with dual pistols allowing a faster firing rate, but eventually he gains access to a shotgun, a rocket launcher (useful for taking down the gargantuan main bosses you encounter), a mini-gun, a Tommy gun (which makes perfect sense, of course), a grenade launcher and a four-barrelled lasergun. Factual accuracy is out. The fusion of science-fiction and ancient Egypt, ala Stargate, is in.

Also aiding Sam is Netrisca. She's the Ziggy to your Al: she gives you hints when you're faced with locked doors and other head scratchers. Her messages will pop up on the bottom right hand corner of the screen from time to time. You can ignore them, but they do help, and the background text she provides on the enemies and the levels adds some flavour to the Serious Sam broth.

Like the feel of the shooting, the level design and mechanics are distinctly old school. The bulk of the gameplay involves moving from room to room (or large open area to large open area), killing what feels like endlessly-spawning enemies that rush at you at every opportunity, with the odd weapon pick-up, health pack and rudimentary puzzle solving thrown in for good measure. Some large rooms contain bosses. Some large rooms require you to kill a number of enemies before you can proceed. Almost every room, though, requires you to kill something. The sheer thrill of shooting stuff in first-person is what courses through Serious Sam's veins.

Long terms fans will know all of this of course. They'll be interested in what's new, and, perhaps, what's the same. Rest easy: SSHD is just as mental and just as barmy as it was eight years ago. All the classic one liners are intact: "This is serious!" "Yeah baby!" It's not a dumbed down experience designed to be more conducive to modern tastes. It hasn't been tweaked to appeal to the Halo/CoD generation. Oh no. SSHD sticks two fingers up at both of those games while using the other hand to fondle old school shooter fans' testicles.

What is most definitely new is the graphics. The new HD look is genuinely impressive. The lighting is great, the hieroglyphs are wonderfully detailed and the bosses look fantastic. The whole game is drenched in a sandy colour, but there's lovely blue skies (remember them?) to gawp at and the odd mix-up. For example, one level sees you fighting in the Memphis Suburbs - it's a jarring combination of modern day structures and ancient Egypt gold.

Some enemies are huge. Very, very huge.

Perhaps the biggest draw for old school fans however, will be the addition of 16 player online co-op for the PC version (four players can play through online co-op on Xbox LIVE). Serious Sam HD looks like madness in single-player. Add more players to the mix and who knows what'll happen.

SSHD is designed to help build up interest in all things Serious Sam so that it won't feel completely out of the blue when Serious Sam 3 comes out, but that's probably doing the game a disservice. While most interest will come from long term fans, from what I've played it'll be worth checking out - even if you've never had the pleasure of hearing one of Sam's one liners, or the thrill of sending a rocket speeding towards the head of a multi-story demon.

Serious Sam HD is due out on PC and XBLA at the end of October.