Marvel's confidence in the project grew with each new piece of footage to the point that last month it announced a sequel for 2017 before the first film had even hit cinemas. With all that in place, there's nothing for Marvel to do other than sit back and watch the money roll in.
What then can Marvel learn from the first space-faring adventure of Star Lord, Rocket, Groot, Drax and Gamora? Let's take a look....
There's nothing left to fear, except a lack of fear itself
Next up for Marvel is Avengers: Age of Ultron, a sequel to the third highest grossing film of all time and about as assured a box office money-spinner as you're ever likely to see. While there will always be certain worries about releasing a film of any kind, it is going to be a long time before Marvel releases a film as risky as Guardians of the Galaxy again.
For Marvel, getting off the ground with Iron Man in 2008 was its first major gamble, then came adapting sci-fi fantasy hodge podge Thor for the big screen, followed by bringing everyone together in 2012's Avengers Assemble.
With Guardians it has now made a success of a comic few had heard of, so what exactly does Marvel Studios have left to fear? The list of reasons it has to be confident grows each year, making complacency the only thing left to be fearful of.
Doctor Strange will enter production within the next year, introducing a magical side to the Marvel Cinematic Universe (MCU), but if it can make Guardians work, why not that? A Runaways film starring teens with superpowers seems easy now. A Black Panther movie? A Ms Marvel movie?
Now Marvel has put a talking raccoon on the big screen, the only thing left to fear is its own cockiness.
Never lose that sense of humour
One of the reasons Marvel Studios' run of films have worked so well for me is the sense of humour running through them. The chief reason for that is Iron Man.
Director Jon Favreau made a film that perfectly suited the effervescent charm of Iron Man actor Robert Downey Jr. It was funny, it was light, it was a classic which created the Marvel mould.
That sense of humour has lingered in every film since, being most prevalent in Avengers Assemble and now with Guardians of the Galaxy, which could well be Marvel's funniest film to date.
A lightness of touch is crucial to making the inevitable darker moments of peril feel weighty and important while also off-setting the obviously ludicrous nature of men in metal suits, Norse Gods walking among us and enormous green rage monsters.
These characters don't lend themselves to darker material as easily as the more plausible Batmen of the world, so why bother? Marvel must never lose sight of this and keep its films comparatively light, nimble and popcorn-flavoured.
Always mix things up
Recent Marvel entries had adhered to a formula common in other superhero films – of which there are obviously a lot. In Thor: The Dark World, Captain America: The Winter Soldier and for variety's sake Superman reboot Man of Steel – the end has always involved a lofty threat to millions of lives and a heck of a lot of explosions.
If the world is always in danger and always saved then eventually – and it has started already – audiences will stop investing in those stories. Sure we know the good guys will save the day, but when billions are saved every few months even the most ardent viewer will begin to groan when supervillain #421 declares his world-obliterating intentions.
Guardians also ends like this, but does enough along the way to keep things fresh. The film could easily have ended differently, with a more personal threat and still had the desired effect. It's possible to tell a meaningful tale on something other than a global or galactic scale.
Never chase the big name directors
Marvel's success as a brand is built upon its constant efforts to keep that brand at the forefront of people's minds, rather than any particular star or director. Only Robert Downey Jr has done this, but at the time of 2008 he was no different to Chris Hemsworth as Thor or Chris Pratt as Star-Lord.
As is the case with its stars, Marvel has always picked its directors wisely and with no regard for a lack of blockbuster experience. In fact, with the exception of Joe Johnston directing Captain America, not one person that has directed a Marvel movie so far has had previous box office success with a blockbuster.
Each director chosen so far has had a particular vision that has made their film stand out. A great choice of director can bring everything together, and that has been no more evident than with James Gunn and Guardians of the Galaxy.
Never be afraid to be silly
As Marvel delves deeper into its back-catalogue, the success of Guardians and its insane roster of characters will be important. It serves as proof that audiences are more willing to accept the strange than Hollywood execs would have feared, and that opens up a world of possibilities. A galaxy even.