When the creator of a virtual reality world (Mark Rylance) called OASIS dies, he releases a video in which he challenges all OASIS users to find a secret "easter egg" which will give the finder his fortune. Wade Watts (Tye Sheridan) finds the first clue and starts a race that'll seen him band together with an unlikely group of players against a ruthless businessman (Ben Mendelsohn) bent on controlling the fate of OASIS.

There are moments in Ready Player One that could be as sharply polarising as any political argument or sporting event you can think of. So much of Ready Player One is built around nods, winks, references that it'll either make you squeal with delight or have you rolling your eyes so hard that they'll ultimately detach. There really is no middle ground with it, and that's part of the fun - it's all so unashamed in itself that for someone like Steven Spielberg to be behind the camera makes it all the more fascinating. There's been something of a consensus that ever since Schindler's List and Saving Private Ryan, Spielberg has forgotten how to make a fun movie experience for audiences. Sure, there's been some exceptions - Catch Me If You Can, The Terminal, Minority Report - but these have been awkwardly sandwiched between the likes of Munich, Bridge Of Spies or Amistad. Within the opening twenty minutes of Ready Player One, it's abundantly clear that this is Spielberg at his most entertaining - and unashamedly so - in years.

The central premise of Ready Player One is pure Spielberg, and in a way, it's kind of recursive but it works. Tye Sheridan's character, Wade Watts, fits the bill perfectly as a Spielberg leading man - all nebbish energy, but with an earnest cause, whilst Ben Mendelsohn's oily, clawing businessman has all the boo-hiss moments you'd need in a film like this. Mark Rylance and Simon Pegg float through the story as plot points, and the supporting cast of Olivia Cooke, Lena Waithe, Philip Zhao and Win Moriaski all fill out their roles well, but it's how each of these characters are rendered that makes the film. So often it seems that CGI can be utterly soulless and devoid of charm or character, but here, Spielberg embraces the sheer absurdity of Ben Mendelsohn's avatar looking vaguely like a musclebound Clark Kent or Lena Waithe controlling an Iron Giant from Brad Bird's animated film.

The animation and the technical brilliance of Ready Player One, combined with the pacing and the sense of joy, is what pushes it all together. Again, it's a polarising thing. If seeing the DeLorean from Back To The Future ripping through a battlefield that features numerous characters from videogames and popular culture does nothing for you, then none of the film will likely work. In fact, one entire sequence of the film is set inside another film - it's better if you don't know which one - and manages to do so in a way that pokes fun at its own absurdity whilst being a technical achievement in its own right. It's crazy stuff, and to see someone of Spielberg's stature attack it with such glee reminds us that he used to make fun and wildly entertaining stories - and he can make them again.

Of course, the flipside of all this enjoyment is that it's all based on the back of previous work and endless references. The screenplay - by author Ernest Cline and Zak Penn - features some desperately clunky moments and gagging dialogue such as, "A fanboy knows a hater," and more than a few motivational speeches that are way too earnest and needy for their own good. This, however, is Ready Player One's charm - it's so earnest, it's so unashamed in itself, and so fully embraces it all, that you have to marvel at it all. While it's by no means perfect, and the slightest bit of cynicism will pull it all down, Ready Player One is - if taken in the spirit it was made - a joyous romp through pop culture by a director who's found the fun in his work again.