Uprising, the first expansion to last year's excellent RTS Command & Conquer: Red Alert 3, is a curious beast. It's a download only, standalone, entirely single-player experience. That's right, we said entirely single-player experience.

Which is a strange choice from developer EA Los Angeles. The best thing about Red Alert 3 was the co-operative campaign - well, that's we we thought anyway. Perhaps the decision to provide four new single-player mini-campaigns and a vast single-player Challenge mode is an indication that we were wrong. RTS expansions exist to give fans more of what they liked from the games they're expanding upon. That there is no multiplayer in Uprising suggests that most people who bought Red Alert 3 played it on their own.

True or false, what we have here, for £15 from the EA Store, is an expansion that at times impresses by making you feel like an RTS god, then disappoints because it falls short of the high-quality spectacle that was the original, and feels, well, just a bit lonely.

Uprising picks up where RA3 finished. At first only the Soviet mini-campaign and the bonus dungeon crawl mini-campaign are available. The Soviet campaign begins with a trademark tongue-in-cheek live action clip (Uprising brings half-an-hour's worth of new footage). The Allies, having dealt with the Soviets and the Empire of the Rising Sun, and with Tim Curry's Premier Cherdenko safely behind bars, are wallowing in the glory of their victory. European Union president Rupert Thornley, played by Malcolm McDowell, is addressing the media, downplaying rumours of a Soviet resistance force. It exists of course, as we soon discover, and we're in charge of making it work on the battlefield, with a little help from the returning Intelligence Officer Dasha Fedorovich, who's still showing just enough boob to distract us from the Days of our Lives acting.

Completing the first Soviet mission unlocks the Allied Nations and Empire campaigns

Uprising is hard, as the very first mission, one that unlocks the Allied Nations and Empire of the Rising Sun campaigns, proves. With a small infantry force you're charged with rescuing captured scientists integral to the resistance effort. It's a tough challenge, even on the easy difficulty setting, and sets the tone for the rest of the game, but it is doable. This isn't a criticism; it's more of a warning (although why the Allied Nations and Empire mini-campaigns need to be unlocked at all is beyond us). RTS expansions usually begin with nary a care for newcomers. They're for players who've honed their skills on the main game. Despite the fact that Uprising will work without having the original, it still follows this RTS expansion convention religiously.

One of the main criticisms of RA3 from hardcore players was that the shoddy AI made things too easy. The AI is similarly silly in Uprising, but you'll still need decent skills to get your £15's worth. Free from the need to balance units, there are moments experienced in the three main faction campaigns that seem designed to test your patience to its limits. The game will at times just open up a new front and fire waves of enemy units at you. You'll die often, quick reload, then try again. Some fans will love the challenge. Others will find it unfair. That's just the way it is.

More of a problem, however, is the lack of co-op. That the game's new maps, all playable in a single-player only Skirmish mode, can't be taken into online multiplayer is something that's just about forgiveable, but why not make the mini-campaigns playable co-operatively? It would have added excitement to what's an at times underwhelming set of missions. Bah.

The live action footage suffers from the same below-par feel. Uprising's eclectic cast of actors, which includes the aforementioned Malcolm McDowell, Holly Valance and ex-wrestling star Ric Flair, do a decent job, but there's something lacking here, something RA3 had. Maybe it's that they don't feel as over-the-top and downright silly as they did in the original, or don't seem to have had as much money spent on them. Whatever it is, they don't captivate as they did in RA3.

If there's one thing RA3 does better than any other RTS, it's water.

It's through the mini-campaigns that you're introduced to the 12 new units Uprising brings to the RA mix. Each faction gets four. Highlights include the Allied Nations' Cryo Legionnaire, a Mr. Freeze-esque infantry unit that, predictably, freezes everything in place; the Empire's Giga-Fortress, a giant robot head that fires an insane amount of missiles, and the Soviet Desolator, an infantry unit that melts enemy infantry with toxic green goo. Every unit fits the RA universe perfectly. They're unmistakeable on the battlefield and clearly designed by a team having a hell of a lot of fun. And as far as RTS expansions go, 12 new units is a generous helping. It doesn't quite make up for the lack of a completely new faction (the Dawn of War expansions showed how to do it), but fans will enjoy getting to grips with them nonetheless.

Where Uprising shines is in the fourth mini-campaign, a three mission dungeon crawl (a first for the series) that feels more Diablo than it does RA. In it you assume control of a single unit: the Empire's commando Yuriko Omega, as she escapes from various prisons at the beckoning of her sister. Remember Testsuo from classic anime Akira? Imagine him wearing a Japanese schoolgirl uniform while tearing up Neo-Tokyo and you're halfway there.

Yuriko's psychic powers allow her to do a devastating infantry popping area of effect attack, force enemy infantry to fight on her side via mind control, shield herself from enemy fire and finally (and best of all) lift vehicles and bits of the environment such as exploding barrels (what else?) and send them slamming into whatever you want. Class.

Uprising is often fun, but we were hoping for more from RA3's first expansion.

Yuriko's three missions aren't hard. In fact you might call them easy. But difficulty isn't the point here. The primal thrill of devastating everything that gets in your way makes up for the lack of challenge. You're having so much fun sending enemy tanks smashing into each other that the repetitiveness of it all doesn't bore. It's designed to be a diversion; an amusing aside, and nothing more.

Which sums Uprising up, really. Without any multiplayer at all there's no reason to replay any of the mini-campaigns once they're completed. The Commander's Challenge mode, which pits players against AI commanders in 50 unique one-off scenarios, will hold your attention more stringently, but again, once you're done with, that's it. Uprising's over.

Uprising's decent value at £15, but without any multiplayer features it lacks longevity and feels at odds with the original game. It introduces some nice new units and successfully makes a move into the dungeon crawl arena, but ultimately it's an underwhelming experience that never hits the spectacular heights of the game that fathered it.