Forza Horizon 4 is built around seasons. In its opening moments you drive a McLaren Senna across autumnal country roads, race a Polaris RZR across a frozen winter lake, skid through mud in a Ford Fiesta in spring, before hopping back into the Senna for a road trip on a clear summer's day. It's a montage of the series' trademark aspirational playground, here tailored to maximise the differences between its seasonal shifts.
Once you reach the festival site, you play through each season individually across a five-hour prologue that introduces Forza Horizon 4's many different events. But after you've completed a full loop—summer to spring—Forza Horizon 4 reveals its final form.
You can still play [with drivatars] in Forza Horizon 4, but by default will load onto a map shared with other players. Seasons progress on a seven-day timer, and each brings specific events, and daily and weekly bounty challenges.
For the most part you and the other drivers on the map will be doing your own thing, driving between singleplayer events, hunting for rare cars hidden inside of barns, or just tearing through a field trying to build combos and (unsuccessfully) run over sheep. You can challenge other players to head-to-head races, or invite them into a convoy in order to compete in co-op or PvP events, but, unless you're actively grouped, you can't physically interact. Drive into another player and you'll pass through harmlessly—preventing would-be trolls from messing up your skill chains.
The racing remains peerless. It's a perfect blend of forgiving arcade handling with an obsessive attention to detail that ensures each car feels just different enough. It's not aiming to be a perfect simulation, but the weight, speed and torque of each vehicle give it a personality beyond class and category.
Forza Horizon 4 has been entirely smooth in my tests. I've played on two machines, one with a GTX 1080 on a 1440p monitor, and another with an R9 Fury X in ultrawide, and haven't experienced any issues—even when cranking the settings above the autodetected recommendations. Unfortunately, the game is exclusive to the Microsoft Store, which remains a terrible user experience.
The best thing I can say about Forza Horizon 4 is it's worth enduring the pain of the Microsoft Store for. But where Forza Horizon 3 quickly established itself as my favourite racing game, FH4 isn't quite as noticeable a step up. It's still an incredible sandbox, with a consistently satisfying loop of fun and rewards, but its differences won't be apparent until the weeks and months to come, and the success (or not) of its seasonal event structure. What's already here is beautiful, entertaining and polished, but it's not yet clear if it can maintain the promise of the festival that never ends.
Unless you're looking for a hardcore sim, Forza Horizon is still the best racing series around.