When a game adopts a floppy disk as its save symbol, you know you're in for an old-school experience. It's not as if you'll need the hint, mind you; Avalanche Studios' Renegade Ops is a top-down twin stick shooter that finds you committing arcade genocide, mowing down entire armies of bad guys in your bullet-spewing death car.

It's a setup that instantly recalls the coin-op machines of the late '80s, a time when - in the realm of gaming, at least - it was perfectly viable for World War III to be settled via the efforts of a lone, super-powered vehicle. Meanwhile the game's cutscenes play out like a low-animation riff on the kids cartoons of the same era - a swear-y GI Joe clone, with cardboard cut-outs in the leading roles.

It's all very knowing, but underneath the nod-and-wink nostalgia lie the same engines that powered Just Cause 2. The use of Avalanche 2.0 and Havoc is most evident in the weighty movement of your vehicle, in the way it swerves and slides in the dirt as you attempt to avoid yet another incoming missile. The first level does a decent impersonation of Just Cause 2's tropical playground, and while the other eight aren't quite so lush, they're all surprisingly expansive.

Each of the four character vehicles is equipped with a special weapon or ability. One can protect himself with a temporary shield, the two female characters can trigger an EMP blast or airstrike, while the final chap can turn himself into a lethal but immobile turret. Provided that you're not playing on the Easy setting, there's also a levelling system that allows you to invest XP in a three-way skill tree, with branches for boosting your offence, defence, and aforementioned trick. The latter is the only major point of variation between the quartet on offer, but you'll be grateful that the choice is there, and the unique abilities become increasingly useful as you level up.

Shave away all these minor complications, however, and you're left with a traditional twin-stick blaster - and a rather demanding one, to boot. There's no pussyfooting around here, just a teeming mass of enemy troops, craft and turrets, all of them spitting bullets and missiles in your direction. While every other exploded foe will drop a green health pick-up, extra lives are far rarer; run through your meagre allocation, and you'll have to start over.

The genre has always adopted this harsh structure, but it feels extra punishing here due to the fact that excursions in Renegade Ops can take up to half an hour to plough through. If you've taken a beating along the way, the final furlong of a given mission can be genuinely tense, and while that's certainly no bad thing in and of itself, repeated failure under such circumstances can sap your will to play. You do get to keep any XP you earned during a botched run, but at the time this will likely seem a minor consolation.

Two issues threaten to exacerbate the situation. The first problem is the handling model: while it's certainly fun and rather satisfying to swerve about the terrain, your plucky vehicle lacks the immediate responsiveness that we've come to expect from a demanding shmup. There's a need to anticipate your needs, rather than react to them, and this is easier said than done when all hell is breaking loose. That said, the added challenge does make it extra satisfying when you successfully deal with one of the more dangerous enemy types - swerving around a massive tank, pelting it with bullets, flirting with disaster but always remaining one step ahead of its life-ending turret.

Your relationship with the controls will improve with time, but it's surprisingly easy to get trapped (albeit temporarily) in cubby holes at the edge of the scenery. More annoying still are the occasions when a quirk of physics pitches your vehicle onto its side, leaving it utterly unable to move or return fire. You'll only be stuck for a second or two, but that's more than enough time for disaster to strike. Heavier enemies can decimate your health bar with a single hit, and it's teeth-grindingly irksome when this happens as a result of a diminutive bump in the road.

The second problem lies with the fact that your primary mission assignments are timed, and yet your exact allowance is never specified. A three-minute countdown appears if you've been taking too long, but there seems to be little consistency in terms of when this appears. Some tasks can be completed leisurely, while others will all but force you to abandon combat altogether, racing through enemy fire to reach the next objective. Missing an appointment results in total mission failure, so it makes sense to sacrifice everything if the timer is close to expiring, even if this leaves you in a sorry state for your next job.

There are other annoyances. If you've not used your special ability or secondary weapon for a while, a massive arrow will flash on screen to remind you of their existence - even after you've been playing the game for hours. Some missions require you to capture buildings by driving into them, at which point you're forced to hammer a button until a small gauge fills, accompanied all the while by a cycling series of comic book panels. It's a cute touch the first time it kicks in, but it's a pointless mechanic that grows increasingly tiresome with each repetition.

To be blunt there were times over the past week where Renegade Ops drove me mad. I'm not convinced that the game works well in marathon sessions; it's always a blast when you sit down to play, but after a solid hour or two the flaws become more noticeable, and the repetition starts to grate - not just the nature of the action, but the relative paucity of new enemy types, and the absence of anything more tactical than the old circle-and-shoot.

I also think that the lengthy levels work against the game's styling as a score attack exercise. The beauty of something like Geometry Wars 2 is that a single game only lasts a few minutes. You try your best, fail, then give it another go. Over an hour you may only have one or two killer runs, but you'll feel that you've earned your success. Renegade Ops has all the leaderboards you could want, but it'll take you a long time to grind out a worthy high score. Even when you know each stage like the back of your hand, it'll still take you at least 15 - 20 minutes to beat a single level.

As a single-player experience Renegade Ops is a tough grind, and the presence of a super-tough Hardcore setting confirms that this was always Avalanche's intention. Difficulty doesn't always equate to fun, however, and when played alone the game can start to feel like hard work. Luckily there's also a decent set of options for co-op play: up to four of you can head into battle online, while local play allows a pair to split the screen - either via a set boundary, or using a Lego Harry Potter-style dynamic divide.

Under these circumstances, Renegade Ops takes on a different hue. With additional players, it's harder to fail a mission - if you lose all your lives you can keep on blasting, but you won't get a score upon completion. With friendly allies, you suddenly feel the freedom to mess about, to gleefully smash a hole through destructible buildings, to pick the turret-based character (it's suicide to choose him if you're on your own). The game feels a lot more relaxed as a multiplayer experience, but thanks to the reduced emphasis on the pursuit of individual high scores, it's also a shallower endeavour.

Then again, what depth did you really expect? This is a throwback to the golden days of arcade shooters; it's supposed to be mindless. For all my criticisms, there's a lot of fun to be had here. The opening level is glorious, the comparative lack of pressure allowing you to simply revel in the carnage and the graphical niceties. You start out in a gunboat, blast through your objectives on land, and then hop into a chopper for an enormous boss battle. It's great stuff, but there's nothing in the subsequent levels that matches the initial high.

That's the game in a nutshell, really: a brief hit of retro goodness that loses its enchantment all too soon. If you're looking for a demanding blast from the past, Renegade Ops will sort you out for a week or two; just don't expect to be playing it for much longer than that.