Nintendo has finally detailed the Switch's online subscription service - and it comes with a feature many hoped would arrive for free.

The ability to back up your Switch game saves to the cloud has long been requested. Right now, if your Switch is lost, stolen or damaged, your 100-hour Zelda save goes with it. All your Power Moons in Mario Odyssey? Gone. And the same is true, most importantly, for all your Puyo Puyo Tetris high scores.

So yes, if you want to protect your save files you'll need to pay.

It's a feature Sony also locks behind its PlayStation Plus paywall, but you can still back up PS4 saves to a USB (just as you could on Wii U). Microsoft, meanwhile, offers Xbox One cloud saves free of charge.

Nintendo's Switch subscription launches at some point in September and costs £18/€20/$20 for 12 months, or more if you want to buy in three month (£7/€8/$8) or one month (£3.49/€4/$4) chunks.

That's for one user - you'll need a family plan (a flat rate of £31.49/€35/$35 per year) to allow multiple accounts on your Switch to access the service. But up to eight accounts on multiple systems can be added to a 'family', meaning you can actually get a good discount if you have seven friends willing to share.

As previously announced, the service unlocks access to a library of NES game with added newly-online multiplayer. We knew about some of these already, but Nintendo has now confirmed that 20 games will be available at launch. These will include:

Soccer

Tennis

Donkey Kong

Mario Bros.

Super Mario Bros.

Balloon Fight

Ice Climber

Dr. Mario

The Legend of Zelda

Super Mario Bros. 3

There's no new option for voice chat - meaning you're stuck using the separate Nintendo Switch Online App through your smartphone. (Or, you could just use Skype or Discord or Messenger for free.)

And then there's the thing you're actually paying for - online multiplayer. You'll need an online subscription to continue playing Mario Kart 8 Deluxe, Splatoon 2, Arms and Smash Bros. (when it launches) over the internet.

After a long delay and considerable wait for Nintendo to roll out its online service plans, today's details feel a little deflating. Its NES game catalogue - albeit with added multiplayer - feels worn out by its repeated release on Wii, Wii U and 3DS Virtual Consoles, not to mention NES Mini. Cloud saves, something people hoped would be added for free, being a paid-for feature is disappointing. And yet it's the only way I'm going to back up my 100-hour Zelda save. So I suppose I better pay up.