Four things to expect from Super Mario Run
It's the day that fans of mushroom-eating mustachioed Italian plumbers have been waiting for - the launch of Super Mario Run.
The game, designed to be played entirely on your mobile phone, comes out on Thursday.
It's set to be the biggest mobile game since Nintendo's last one - Pokemon Go.
With the help of Japanese gaming expert Dr Serkan Toto, here's what we know so far.
It's going to be huge, we're told
Dr Toto has been based in Tokyo for more than a decade, advising businesses on the mobile gaming market.
He's in no doubt that this release is a big deal.
"Mario is the biggest, most iconic video game character on the planet. Period.
"When you have the most iconic character who's ever existed in the world of games entering the mobile game space for the first time, you can almost speak of a small revolution.
"So far Mario has been reserved for hardcore video gamers who'll pay $350 for a console and another $60 for a game.
"Now all of these barriers, all of that friction, has been removed."
He thinks the app will join the likes of Candy Crush and Fruit Ninja in topping a billion downloads, although some early reviewers have been critical of the fact that you can only use it when you're connected to the internet - even in single player mode.
You can play it while eating a burger
Fans of the classic Mario games will be pleased to hear the gameplay is exactly as you might expect.
You run, jump on platforms, eat mushrooms and try to avoid enemies. There's one big difference, though - Mario runs all by himself.
This means you can play the game one handed, leaving your other hand free.
We'll let Mario's creator, Shigeru Miyamoto, demonstrate.
It may change the games industry
"Super Mario Run will definitely be one of the biggest mobile gaming launches of all time," predicts Dr Toto.
"It's a big deal for Nintendo but also for the entire mobile games market."
He thinks it could pave the way for more iconic gaming characters making it onto your phone.
"For mobile games I would say that - and maybe this is a slight exaggeration - that the history books will remember an industry before Super Mario Run and after Super Mario Run."
And it could also have big implications for Nintendo's future.
"Nintendo's latest console, the Wii U, has absolutely flopped," Dr Toto explains, "in American school grades it's been an F.
"So they absolutely need a hit in the mobile market so they can use it as a future model of growth, especially if their next console turns out to be a flop too."
It won't be free
You'll be able to download a demo version of the game for free, but the full version is going to cost £7.99.
This is unlikely to put off hardcore fans like Amjid Khan from West Yorkshire.
"I've been playing Mario ever since I've been young, I think it's fantastic," he tells Newsbeat.
"I'm excited about the fact you can play it with one hand - or on the bus or on the train.
"I can't wait for it to come out."
Find us on Instagram at BBCNewsbeat and follow us on Snapchat, search for bbc_newsbeat