It goes without saying that every writer-director wants their films to succeed; not only when it comes to box-office numbers but by genuinely pleasing cinema-goers too. But when your film is preparing to be a franchise – just as James Gunn's 2014 Marvel outing Guardians of the Galaxy was – there's always that worry that if you completely knock it outta the park, how are you ever going to best it?

Given that it made upwards of half a billion dollars worldwide and wowed comic book fans and critics alike, Gunn undoubtedly felt the pressure when he sat down to pen the inevitable sequel, aptly subtitled Vol. 2. Long story short, the pressure was on. The first movie was so full of surprises despite existing in such a formulaic genre, that it was a refreshing glimmer of hope. But surely the curveballs are going to run out sooner or later and the need for structure will kick in...

Guardians of the Galaxy Vol. 2 (6/10)

After saving the entire universe from Kree radical Ronan (and his puppet master Thanos), lauded heroes Peter Quill (Chris Pratt), Gamora (Zoe Saldana), Drax (Dave Bautista), Rocket (Bradley Cooper) and Baby Groot (Vin Diesel) find themselves scampering for their lives across the cosmos after stealing some high-priced batteries from an obnoxious alien race called The Sovereign. (Which apparently, is the greatest heresy – who knew?) Thinking that their luck has run out, the group find an unlikely ally in Ego the Living Planet, an ancient celestial entity, whose physical self resembles Kurt Russell and claims to be Quill's father. Well, tradition rules that it wouldn't be a proper space opera without daddy issues now, would it?

With the first film teasing Quill's heritage throughout, it's hardly shocking that the sequel addresses such matters, meaning that the only area Gunn really allowed himself room to shine was with an epic new threat for the titular to face off against. Because of course, as with any superhero movie, the heroes are only ever as good as their baddies.

Disappointingly, having proved her villainous chops in The Man From UNCLE, Elizabeth Debicki is sorely underused as ''antagonist'' Ayesha; the golden leader of The Sovereign. There's a reason she's sidelined and it doesn't take a genius, or even someone familiar with Marvel, to realise who she involuntarily bows out in favour of...

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Elizabeth Debicki is sorely underused as leader of The Sovereign, Ayesha Marvel Studios

Okay, so Ayesha (and others) fail to step out of Ronan's shadow, but what of the film's other variables? Well, the soundtrack is good. There's some hugely enjoyable tracks in there including Mr Blue Sky by Electric Light Orchestra which acts as the backing track to a truly wonderful opening sequence, and the electrifying bass-heavy remix of Fleetwood Mac's The Chain is a particular standout. But compared to the first's, which made every beat count, it can't help but feel a little sub-par.

The missteps filter down even further than the tunes too. Sometimes less is more, and while the first film pushed those boundaries and ended up being a ballsy, highly-enjoyable explosion of action and colour, the second movie ignores such boundaries completely. Drax inappropriately laughs at everything, Rocket swaps sarcasm for outright rudeness (for a reason, but still) and Quill becomes little more than a man making goo-goo eyes at fellow member Gamora. Fortunately, the characters themselves are just as charismatic as ever and largely make up for the script's zany over-the-top approach.

When Guardians of the Galaxy Vol. 2 isn't exploring Quill's downright predictable backstory, it makes way for almost all of the supporting players to have their own arc; particularly Rocket, Yondu and adoptive sisters Nebula and Gamora. As Quill pines and attempts to develop the "unspoken thing" between he and the latter, she – albeit reluctantly – keeps him at arm's length, allowing herself to be a fully-fledged character in her own right rather than simply a love interest.

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Kurt Russell stars as Ego the Living Planet, a celestial being that claims to be Peter Quill's biological father Marvel Studios

Gunn doesn't just concentrate on faces we recognise either. Pom Klementieff's Mantis is a brilliant new addition, with her openness – strengthened by her superhuman ability to feel empathy – balancing out Drax's matter-of-fact nature and adding some much-needed heart to the prickly existing gang. Make no mistake though, you'll find your eyes searching for adorable Baby Groot in every scene.

But by concentrating on individuals pasts, Gunn seems to forget about the now, and much of the film struggles with pacing issues and occasionally nonsensical and lacklustre plot. The action-packed set pieces are thrilling when you're watching but once you walk out of that cinema, you'll be pushed to remember anything as strong as the legendary ''Kyln Escape''.

Given the emphasis on humour in the sequel, it's a wonder then why Gunn also felt the need to double down on emotion. Certain plot points made its inclusion inevitable, sure; Quill forging a relationship with Ego or Nebula coming to terms with the tragic reason she's so robotically enhanced to name a few. But it's hard to really feel the gravitas of such moments when ten minutes ago, Baby Groot was ''accidentally'' severing off someone's toe or Drax was boasting about having "famously large turds." As a comedy, Vol. 2 is a bonafide triumph. As a drama, it doesn't cut the mustard.

Even set against the mind-bending Doctor Strange, Guardians of the Galaxy Vol. 2 is one of the Marvel Cinematic Universe's weirdest instalments to date. Something that litters it simultaneously with both rolling positives and negatives at several different points throughout the movie.

However, there's one thing for certain, it brings the fun and is packed full of belly-laugh moments and dazzling visuals. It's a different beast than the original; much more self-aware and silly – trust us, it's possible – which sometimes misses the mark. But if the gags were what you loved most about the first outing, you're not going to be disappointed this time round.