Buy it if the people you race with are not all on the same machine. It is the only current four-player split-screen racer that runs on PS5, Xbox, PC and Switch - and crossplays between them
Short verdict: Sonic Racing: CrossWorlds is not competing with Mario Kart on quality. It is competing on reach, and on reach it wins outright. Up to four players in local split-screen, up to 12 online, cross-platform multiplayer, and it runs on PS5, Xbox, Switch and PC. No other kart racer in this catalogue does all four of those things, and every Nintendo racer fails the last two by definition.
That makes the buying advice unusually clean. If your household is a Switch household and the racing all happens on one sofa, Mario Kart is still the better game and the easier recommendation. If your group is a PS5 in one house, an Xbox in another and a PC in a third - or if the console in your living room simply is not a Nintendo one - CrossWorlds is the purchase, and it is the only one.
Is Sonic Racing: CrossWorlds crossplay? Yes, and that is the whole point
Its listing carries cross-platform multiplayer, which means the PS5 player, the Xbox player, the PC player and the Switch player are in the same race. For a kart racer that is close to unique: Mario Kart World and Mario Kart 8 Deluxe have no crossplay and never have, and Crash Team Racing Nitro-Fueled's online is same-platform only. The crossplay hub runs this check across every category on the site, and the inverse list names a substitute for each big title that does not have it - CrossWorlds is the substitute it names for Mario Kart.
Is it split screen? Yes, for four - including on a PC, which is rarer than it sounds
Up to four players in local split-screen, and its Steam feature list carries the Shared/Split Screen flag - which matters because, as our split-screen racing page sets out at length, PC racing games almost never do. Two of the racers we recommend have that flag at all, and this is the only one of the two that seats four. If you have a gaming PC in the living room and four people who want to race on it, this is effectively the answer by elimination.
On console the four-player local cap puts it level with Mario Kart and ahead of everything simulator-shaped, which tops out at two. And as with every split-screen game, four players run from one copy - you never buy four copies for one sofa.
Who should buy it
A group split across consoles. The clearest case on the page, and the reason it exists. Nobody is excluded, nobody has to buy hardware, and you can have two people split-screening on a PS5 while two more join from a PC.
A PlayStation or Xbox household that wants a four-player kart racer. Mario Kart is not available to you. This is the current four-player split-screen option on both machines.
A PC household with four people in one room. See above: the Shared/Split Screen flag on a racing game is rare enough that this is close to the only legitimate choice.
Who should not
A Switch-only household that already owns a Mario Kart. You would be buying a second four-player kart racer to do a job you have already paid for, and the crossplay - the main reason to choose CrossWorlds - is worth nothing to a group that is all on the same console. Kirby Air Riders is the more interesting second racer for that household.
Two people who want real driving rather than items. A kart racer is the wrong genre; Gran Turismo 7 on a PS5 is the two-player split-screen answer and the racing page explains the cap difference.