I could literally fill my entire allotted space here saying what’s wrong with the Manic Street Preachers’ debut album. Far too long; questionably sequenced; lousy quality control; essentially the sound of one gifted but still learning guitarist and singer attempting to turn a series of slogans into actual songs.

But the magic of the Manics' early years is that all these faults are invariably cited as virtues: Generation Terrorists is the key document of the days when the band were a gang of faintly preposterous young provocateurs embarked upon on an extravagant crusade to tell society exactly what was wrong with it. Twenty years later, it feels like a memento from a more innocent time, before the darkness came.

And at its considerable best, one of Generation Terrorists’s greatest virtues is how incredibly young the band sounds: with James Dean Bradfield’s slightly quivering voice, ‘Stay Beautiful’s autobiographical-ish tale of teen rebellion (“all broken up at seventeen… we’re a mess of eyeliner and spraypaint”) and its wonderful chorus - in which a two note riff subs in for the words ‘fuck off’ – is sublime, all the vulnerability and attitude of Bradfield’s Hollywood namesake, exquisite in its faux naivety.

The soul of this record is the healthy clutch of songs here cut from the same cloth, notably ‘So Dead’ (“you’re gonna pay for my intelligence”), ‘Tennessee’ (“our epitaph reads like your sin”) and ‘Methadone Pretty’ (“I accuse history, I accuse”), metallic updates on classic rock’n’roll with lyrics that read like an improbably soundbite heavy mash up of Nietzsche and The Ramones. If they’d wanted to, I suspect the Manics could have made a dizzyingly romantic ten or 12 track debut album entirely in this vein, one that would technically be 'better' than what they in fact turned in.

This didn’t happen – instead the 18-track (19 in this reissue) Generation Terrorists is populated by an erratic series of creations spawned from the DNA of the Manics’ favourite bands: Guns ‘N Roses (‘Slash ‘n’ Burn’, ‘Condemned to Rock’n’roll’) ; The Clash (‘Natwest – Barclays – Midlands – Lloyds’, ‘Repeat’); even, bizarrely, Public Enemy (‘Repeat [Stars and Stripes]’). Some of this stuff is good, some of this stuff is bad: only a lunatic wouldn’t say it was overegged.

Despite the timeless allure of the band’s cheery declaration that they would set fire to themselves on TOTP after selling 16m copies of this record, which would be a double, I do feel that the album’s sheer bulk – combined with the fact that on CD it’s not actually a double - does tend to swamp some of the better tracks. Obscure punk cover ‘Damn Dog’ and ‘Repeat [Stars and Stripes]’ (a polished proto Big Beat dance remix from PE’s Bomb Squad) are eminently B-side-ish, and I think there’s a wider issue with the sequencing: the opening run of ‘Slash ‘n’ Burn’, ‘Natwest – Barclays – Midlands – Lloyds’ and ‘Born to End’ is solidly proficient rather than ball grabbingly arresting – no ‘Welcome to the Jungle’ or 'London Calling'.

But then, of course, we come to ‘Motorcycle Emptiness’, a titanic, six minute beat poem-cum-refutation of mainstream culture that sounds like it was written by a band at least a decade older and wiser, clean riffs singing like rockets and Bradfield’s steely vocals making every line from lyricists Nicky Wire and Richie Edwards sound like some Old Testament proclamation. It is an astonishing song, and in many ways feels like the legitimate end product of the occasionally misfiring ambition around it. ‘Little Baby Nothing’, aka the Traci Lords duet that the band wanted to be a Kylie Minogue duet, is a bit rougher, but with its melodic piano line and discernible sense of narrative it looks forwards to the band the Manics would become while boasting the quintessential slogan-tastic coda of the band’s career, with its immortal line, “rock’n’roll is our epiphany, culture, boredom, alienation and despair”.

These two tracks represent the first appearance of that powerful sense of gravitas that would later define the band. They are, in essence, vastly more advanced pieces of songwriting than the rest of the record, and to a large extent they make up for its shortcomings – yes, some of Generation Terrorists is a mess. But look, in the end they could do this.

It’s kind of to the credit of this 20-year-anniversay reissue that in terms of the main record there’s no airbrushing. The remaster is fairly unrevelatory, merely adding a bit of volume. And there’s the slightly desultory tacking on of the band’s cover of ‘Theme from MAS*H’ at the end (it’s a great cover, but in terms of the impact of the record it slightly pisses on 'proper' closer ‘Condemned to Rock’n’roll’s chips). This rerelease might have been an opportunity to have more of a tinker – prune a couple of tracks, maybe sub in the Heavenly version of ‘Spectators of Suicide’, that sort of thing. But tidying Generation Terrorists up would be untrue to Generation Terrorists and it’s best left as is, I think.

There is an absolute fucktonne of bonus material available with this reissue, depending upon which version one buys. Having already waded through 19 tracks of the basic album, do you really want 43 more songs (mostly demos), plus a DVD documentary? Sure! What emerges from the documentary – entitled Culture, Alienation, Boredom and Despair - is not so much the story of what the record meant, more the story of how the Manics came to make it, from their first London gig at the Horse and Groom, via their short time on Heavenly, and on to the absurdly extended recording session for the album under the tutelage of slick US-based producer Steve Brown.

There is a lot from both Brown and the band on how the youthful, Jasmine Minks-obsessed Manics were sculpted into something approximating a rock band. The bonus music discs represent a fascinating window into the band’s earlier years, when they were a lot more ‘indie’ in sound than the rock act they self-consciously honed themselves into. The Heavenly stuff is here, which is great, but particularly fascinating is ‘Motorcycle Emptiness (South Wales Demo)’, an alluring piece of twee-pop that sounds not unlike the band’s heroes McCarthy, and almost nothing like the final record. The South Wales Demos in general offer a fascinating and far from unpleasant window into a parallel world where the Manics hadn’t shot for the big time.

It’s the archive footage on the DVD disc that seems the most important, though. Richie Edwards didn’t play a note on this album, and it can be hard to visualise his role in the band prior to The Holy Bible. It’s a joy, then, to see him and Wire provocatively fannying around with such abandon – it suited Wire having a partner in crime, more so than being gobshite in chief, and it’s important to realise the band were having a good deal of fun back then. As they note in the documentary, despite the infamous ‘4 real’ incident, Richie’s problems didn’t really start until after the release of Generation Terrorists . These days he tends to be viewed as a perma-troubled martyr, but I think I’d prefer to remember him like this: bolshy co-conspirator behind one of the most wonderfully eccentric debut albums of all time.

More: 'Manics Monday' editorial can be found over this'a way.