Just Cause 3 begins with hero Rico Rodriguez standing untethered atop a plane, firing an RPG at local militia, scattered anti-aircraft guns and anything else that takes his fancy. This is a game that isn't fussed about playing its cards close to its chest, the practised structure of open-world games or the laws of physics – it's a sandbox game in the purest sense, but that may also be cause for concern.

We sat down to play the first two hours of Avalanche Studios' new game, followed by a third hour with many of the game's weapons and vehicles unlocked. The basics are drilled in early on: players run, gun and blow things to hell. However, as the game rolls on, little appears to change beyond the size of enemy bases, the power of those trying to stop you and the size of Rico's arsenal.

Challenges testing skills with various weapons, tools and vehicles dot the map, and offer up mods as reward. Otherwise progress through the game is made by completing story missions and liberating towns and outposts the good old American way – by destroying a lot of stuff, flying a flag and sauntering off. Not that Just Cause 3 is at all satirical – it's wanton silliness and all the better for it.

The characters and script are goofy as hell, but in an endearing way that's refreshingly up front about what it is. Even those at Square Enix prior to our demo were open about only wanting to give players the tools to have fun, then setting them loose on the world. There was no pretense about the story's resonance in modern society or that kind of nonsense, just: "I was playing yesterday and attached a bunch of people to a helicopter."

That's why the game's world is open from the start. The story of Mediterranean revolution will give players the longer, grander tour of Just Cause 3's fictional setting of Medici, but should you desire you can head straight for the most heavily fortified base on the third and final area of the map – just don't expect to survive long.

Just Cause 3
Structures destroyed will respawn once the player is far enough away, keeping the sandbox full Square Enix

As mentioned, the game's basic tools include run and gun third-person shooting and vehicle controls, both of which do their job simply and perfectly well. What's more intricate is how Rico traverses the homeland he's trying to liberate from General Di Ravello (imagine Colonel Gadaffi as a Saturday morning cartoon villain). Vehicle-free travel is handled with three key components – the series' famous grapple, a now-infinite parachute and a wingsuit.

The grapple does the majority of work with the parachute and wingsuit used when necessary to reduce or gain speed over short or long distances. Even after three hours however I didn't feel like I had fully got to grips with the controls and wondered whether they could have been more intuitive. A disregard for physics removes many of the problems that may have surfaced and an excess of health means face-planting at speed doesn't mean an instant death – but I still found myself not moving with the freedom I wanted.

Rico hops on to surfaces (a building's roof or the top of a cliff) if he grapples near the top of the ridge, but often I found myself repeatedly grappling to find the sweet spot or jumping up and slipping back. I'm certain mastering all of this will come eventually, and wield thrilling results too, but as a fundamental part of the game I was left thinking it should be more welcoming.

Just Cause 3 is selling itself on, and will be at its best in, the unscripted moments. Using multiple grapple-tethers to catapult someone into the sun, standing inverted on the underside of a plane to blow up a bridge as the player passes under it or, as seen in one of the demos alongside mine, tethering the bed of a truck the road to make a ramp and watching traffic drive up it.

On PC Avalanche's game will have the support of the modding community that gave Just Cause 2 a longer shelf life than anybody predicted. On console the longevity still comes from the creativity of players, but is limited by what the shipped game and post-release content offers. Blowing things up and completing challenges may well prove enough for a short while, and even enough to justify the entire game for some players, but open world games have changed a lot since we last saw Rico.

The likes of Grand Theft Auto 5 and Metal Gear Solid 5 have given gamers intricate open worlds with systems that create vibrancy and fun from their many interlocking features. In comparison Just Cause 3 feels less alive, and more like a film set for your revolutionary Michael Bay to unleash utter carnage. It's bound to be fun for at least a short while, but Avalanche's deliberately old-school approach may not resonate in quite the same way as Just Cause 2 did five years ago.

Just Cause 3 trailer: Rico Rodriguez is a firestarter in Avalanche Studios sequel IBTimes UK

Just Cause 3 is set for release on Xbox One, PS4 and PC on 1 December.

For all the latest video game news follow us on Twitter @IBTGamesUK.