Multiplayer is the absolute star of the show. With my Philippine-quality internet I get into races in literally seconds. With past games on both Playstation Network and Xbox Live, matchmaking can take 15 minutes or longer. I don't know how Nintendo did it. Maybe Mario Kart is just simpler to code for since it just involves race cars? This game doesn't have the usual issues with driving games on laggy connections. Things like teleporting cars, cars going much faster than you....I have seen none of this happen while I was playing this game, and quite frankly it's shocking. I'm pretty much used to having problems when playing ANY networked game but Mario Kart 8 seems to have none. You can play against nearby opponents in Asia, or opponents in the US and Europe, and none of the matches feel any different. It's like they're literally in the room with you. No weirdness. No lag. No slowdown.
It. Just. Works.
That feature alone sells this game. If you have only five minutes to play, this game lets you. If you want to keep going for hours and be sure that you're always racing, you can do that too. Mario Kart's multiplayer is pretty incredible that it manages to do this with 12 players all at once, and you can even bring a friend to play in split screen, VS. online opponents, who can do exactly the same! You get into full rooms very quickly, and you get to enjoy some great action every time you fire up this game.
Yes, the single player is there when your connection is down and you need your racing fix. It's barebones but at 150cc (the highest setting) it can be pretty challenging too. Track design is spectacular and no two tracks feel the same. There's a lot of really cool stuff in the game's 32-track roster (that is a LOT by racing game standards....).
Overall, this is a game that's pretty hard to ignore. I only wish that the Wii U had more frequent releases. But this game, along with Super Mario 3D World, make the system a must own for anyone who truly loves games.