It's easy to imagine that when Playground sat down to define the essential direction it wanted to take Forza: Horizons in, the big heading with multiple underlines at the top of the whiteboard read “Boy Racer Heaven!”(or “Car Enthusiast Heaven!”, at least). Consider the universe the game presents – a resplendent fictional version of Colorado with a huge network of sweeping open roads and apparently zero police presence. What seems like the state's entire infrastructure has been given over to a massive racing and car appreciation festival that is flocked to in droves by the young, hip and good looking. It's a Neverland where the nearest barn always contains a classic car that any passer-by can find, claim and completely restore at no cost, and where a head-on collision with a truck is merely the slightest of inconveniences. Welcome, car lovers, to your wildest dreams.

In this alternative utopia, the titular Horizon festival seems to be a massive festival celebration of all things automobile, a Glastonbury for gearheads. Driving into the midst of all this action is the player, a young rookie looking to make a name for him or herself. There is a narrative frame here of the most skeletal sort, although it always seems to be more about world-building – continuing the feel of an alternate universe by establishing it as a place where successful street racers are sort of rockstar equivalents. How much of a distraction these narrative elements are from the meat of the game depends on one's personal tolerance for try-hard trash-talking and characters who repeatedly use phrases like “Listen up, dawg”, but these snippets are at least always fairly brief, leaving the player to get on with cruising the open roads in free roaming mode, entering race events around the map, and using their winnings to expand and improve their car collection.

Players are free at any time to cruise the large network of open roads to their heart's desire, and this can be rewarding just in itself. Few open areas are available; arbitrary fences everywhere ensure players stick close to the road, but there are a lot of roads, and it's rewarding to discover a wide, straight stretch where the cars can really be put through their paces, be driven over a majestic dam at sunset, or try to set a new personal top speed at one of the speed cameras dotted around the landscape.

Budding photographers can park their car somewhere and scenic and get to snapping, and treasure hunters might enjoy looking for some of the 100 signs around the map to smash (each affording a 1 percent discount on car improvements added for each one destroyed), or seeking out classic cars hidden away in barns down out-of-the-way dirt roads. The other 260-some drivers in the festival are also cruising the road network day and night and initiating an impromptu cash race is just a matter of pulling up behind one of their clearly marked cars and challenging them. There's lots of little tasks like this to keep players occupied in free roam, but perhaps more importantly the game manages to make driving aimlessly entertaining.

To advance up the festival ranks though, the player needs to enter official Horizon events. These are dotted around the map, and doing well earns the player both money and festival competition points. Horizon drivers must try to earn enough points through competition to level up to the next colour of driver wristband, and each new wristband that is successfully earned opens up new race events around the map. These events are varied in their nature and entry requirements – they can be point-to-point or lap races, on dirt roads, tarseal, or mixed surfaces, and require different classes, vintages or types of car to enter - hatchbacks for example, or only American-made cars. Although it can be slightly frustrating when the map seems to be littered with race events for classes you don't have any qualifying cars for, money is pretty readily earned in the game, and a handy option to instantly upgrade or downgrade any owned cars to meet the required vehicle class for the race is also provided.

As the player progresses up the ranks, “Showcase” events of the festival become accessible, pitting the player's driving skills in special events such as a race against a plane or hot air balloons. Lucrative “unofficial” street circuits also pop up, allowing the player to take part in races where no-one has bothered clearing civilian traffic off the course first (although throughout the game, the good people of Alternate Colorado seem to take the hooligans blatting all over their roads at ludicrous speeds in pretty good stride). These special events provide a fairly regular point of difference from the standard race events, helping to keep the play experience fresh by mixing things up a bit.

Driving itself offers a highly customisable level of realism and difficulty, making the game accessible to all experience levels. Novice racers can elect to have the computer take care of things like changing gears, traction control, and more, and even have the game paint a best-course line that will even indicate when and how hard to brake on the road, while the more hardcore may opt for no assists at all in full simulation mode – although Burnout fans might be disappointed, since even with all the hardest and “realistic” options turned on, ploughing a Ferrari into a metal gate at 280km an hour will result in no more than cosmetic damage. Even with most of the driver assists enabled though, the distinct difference in handling between different car models and on different road surfaces illustrates the depth of the driving physics, and it's easy to experiment with the cars won or bought to find one or two favourites that best fit a driving style or skill level.

At any time you're behind the wheel, the game is also keeping track of player driving style, awarding points for things such as near misses with traffic, burnouts, getting a car airborne, drifting, destruction of roadside items, and so on. Earning these points meets the requirements of reward challenges, but also builds a racer's popularity ranking at the festival, helping to unlock further events. Although this system serves to occasionally provide a moderate sense of achievement, style points are awarded pretty consistently without the player really needing to go to any special effort, making them start to feel more like stat tracking than a reward system for skilful driving - although they're a convenient source of regular income boosts.

At any time players can drive or fast travel back to the centrally located festival race centre to purchase new cars, upgrade parts, or paint or cosmetically upgrade a favourite ride. The options for the appearance and performance customisation of vehicles is extensive, and it's easy to lose 10 minutes just trying to decide which of the many wheel rims on offer look best on a Mini Cooper. There are also social options available at the race centre such as joining a car club where players can share their customised vehicles with fellow club members, or put their creative paint work up for grabs for other players.

The game's multiplayer offers plenty of diversity. There are many of settings available for straight out races - which can most often be partaken in using the singleplayer garage of cars – as well as a multiplayer version of single player's free roam, but also a number of game type variations. Infected starts with a single zombie car trying to ram other players to spread the infection to everyone. In King, players attempt to tag the designated King car to steal the crown, then try to keep it for themselves for the longest total time during the round. Possibly the most fun though is Cat and Mouse – even-numbered red and blue teams each have a Mouse player in a low-speed car, with the rest of their team taking the part of Cats in fast, high-powered cars. Only a Mouse can win the race, leading to a sort of automotive roller derby as the opposing Cat cars try to protect their own Mouse car while stopping the other team's. It's entertaining as a Cat to box in an opposing Mouse and perhaps even flip their car over, but even more entertaining as an underpowered little Mouse to hit the brakes at exactly the right time and watch two opposing Cats shoot past and slam into a wall.

With its somewhat unusual approach for a driving game, Forza Horizons manages something of a coup – it provides plenty of action for hardcore racing game fans, but by setting its races in its gorgeous, activity packed open-world, it manages to add significant appeal for those not normally all that fussed with racing games as well. Most gamers should find many solid hours of entertainment in this title, and most racing game fans will probably wish they could live in it.