Def Jam Rapstar

All songs in the game are backed by their original videos, but these play out in a 4:3 ratio box in the centre of the game screen, a presentation that immediately makes the game look like a cheap karaoke knock-off by comparison to SingStar's slick full-screen approach. This effect isn't helped by the menu design, which features jagged, oversized lettering overlaid on a rudimentary 3D model of a gold city under a blackened sky – a far, clichéd cry from the slick creativity of some of the artists the game features.

The game itself works in much the same way as SingStar. Any sung parts in a song are judged on tuning and rhythm, with a scrolling line moving up and down in step with the changing pitch of the note. Rap notes are marked in much the same way, but here pitch is far less important than rhythm. Dots show the rhythm of each phrase, while the next lyric is shown on screen below the one you are currently singing, enabling you to keep up with sections that you don't know by heart.

Nevertheless, the game is most playable when performing songs with which you are intimately familiar. Attempt an unfamiliar track and following the rhythm of the dots with any sort of accuracy is almost impossible: the notation is simply too crude to act as anything other than a gentle guide. In raps you are scored on rhythm and, allegedly, on lyrics, although the extent to which the game manages to distinguish the words you're using is debatable. Correctly completing lyrics fills a multiplier meter and chaining together lines is the key to high scores.

The structure sits somewhere between that of the plain karaoke simplicity of SingStar and the structured play arc of Guitar Hero. Career mode is segmented into five discrete stages. You earn microphones for performances (these work in exactly the same way as Rock Band's star ratings) and in order to access later stages you must pass a set threshold of mics. Training modes allow you to break songs down and, undoubtedly, as you learn the tracks and practice, improvement is discernible.

Party mode, by contrast, opens up most of the game's track list (bar those few that you unlock in the career), allowing you to cue up medleys and perform with friends either in a co-operative duet or a competitive 'rap battle' for the highest score. Finally, a freestyle mode provides a slew of backing tracks for you to rap over, with the option of filming the results and uploading them to Rapstar's community.

This section of the game is surprisingly well-featured, co-ordinating performances in the game with the official site. You can upload 30-second raps as well as rate and vote for other performances around the world. The videos currently featured on the service are serious, with few comedic ones, 4mm perhaps pre-loading its servers with solemn entries in order to discourage messing about. The option to challenge another rapper to a battle and have the community vote for their favourite of the two performances is smart, and for those players who fully engage with this portion of the game, there's some scope to become known amongst the community and perhaps beyond.

Indeed, 4mm's investment in the community portion of Def Jam Rapstar makes its ambition clear. For some, the game will be a chance to get a bit drunk and mess about singing Gold Digger while pretending to be the wiry-haired teacher off of Glee. And to that end, the game satisfies rather than dazzles.

But for others, Rapstar represents a bona fide opportunity to show their skills to a wider audience. Arguably, with its 30-second limit, these players would be better off uploading their rhymes to YouTube. But if enough people engage with the framework 4mm has erected, this could prove a breeding ground for new talent the likes of which the other rhythm action games can't provide.

Meanwhile, for me, it's a chance to rap alongside Ghostface Killer in the comfortable privacy of a suburban living room. You can't put a score on that.