First conceived as filler between Halo 3 and Bungie's next ‘big' Halo game, ODST seems like it should never have been more than a well-realised expansion pack. But here, thanks no doubt to the marketing brains at Microsoft, we have a fully fledged Halo release. And at first glance it seems quite worthy of its RRP; a title that re-affirms Halo's ‘big moments' approach to gameplay, as well as the many layers of polish that we've come to expect from the developer.

ODST plonks you into the quivering boots of a UNSC Rookie (that's also his name) for a very short single player campaign comprised of chasing down beacons and reliving flashbacks, oh and there's a new multiplayer mode called Firefight, which basically rips off (but is different to..) the Horde mode from Gears of War 2. Thrown into the package as almost an afterthought is a second disc containing the latest version of the Forge level editor, three new multiplayer maps and all of Halo 3's previous multiplayer maps. Ideally, this seems a pretty good deal if you haven't already paid for any of Halo 3's DLC, but Master Chief Veterans, the main audience for this game, are likely to feel like they're paying for it twice over.

ODST's overall focus this time is somewhat different. Because you aren't playing as Master Chief, there's a new health mechanic and HUD to get used to. At any time, the player can press the X Button to activate the VISR (Visual Intelligence System, Reconnaissance). This brightens up the game's largely dark environments and also highlights enemies with red outlines.

While this is often a helpful addition given the game's predominantly dark lighting conditions, the use of a non-replenishing health mechanic is less welcome. Obviously added to reinforce the fact that you're playing a lowly grunt protagonist, it's a demeaning and at times frustrating mechanic, particularly given that the usual Halo design approach has remained largely the same, i.e. heaps of enemies all focused on turning you into a marine pancake.

Where once the Master Chief's replenishing shield and health bar helped to pace combat and allow you to jump back in after a few seconds of respite, ODST's permanent depletion of health – forcing you to find health packs (how original) to restore health – often means that you'll see the same reloaded checkpoints time and again. It's not that ODST is any more or less difficult than the previous games, it just feels a lot more frustrating due to this unnecessary ‘addition'.

The frustration continues throughout the experience when you realise that very little has been done to improve the Halo experience itself. Certainly, kudos to Bungie for attempting to tell a story in their universe in a slightly different manner (complete with piano soundtrack and some slow-paced investigative moments), but ultimately the gameplay still boils down to an approach that they've been recycling since the first game. Too often in ODST your progress will be stymied by bland level design (it never feels like anyone ever lived in New Mombasa), confusing flashbacks (again, kudos for trying but they muddy the story waters) and Bungie's personal favourite: wave after wave of dropped-in enemies.

That I describe the forward momentum of ODST as a series of setbacks should give you a clue that the game is not exactly a well-paced experience. Ostensibly there's an open city to ‘explore' but if all you do is follow the waypoints given to you, you'll find the required backtracking to be unnecessary and boring. As a result, ODST becomes a series of ‘go here' moments, with no particular motivation to actually do so apart from a desire to unlock the next achievement and, in the end, complete this incredibly short Halo vignette. Any attachment to characters is fleeting and you never feel like you're getting a grasp on the larger narrative picture.

There's no replayability in the single player game, unless you really want to track down all of the audio logs (aural additions that only serve to highlight the eerie sterility of the city you're wondering around in). Having a multiplayer-only disc thrown in is certainly handy, but it glosses over the fact that there's little on offer here to entice fans other than the single player game.