SimCity developer Maxis has insisted the game's always-on internet requirement is "worth it".

SimCity, due out next year exclusively on PC, is not playable offline - something that has upset a number of PC gamers.

According to Maxis producer Jason Haber, the way SimCity's hush-hush multiplayer works means it's better to have players connected to the internet at all times - and once the features of the game are fully unveiled at the E3 trade show in June, players will agree.

"From the ground up it's been a multiplayer game," he said. "I'm not surprised we're getting some reaction like this. But I think once people see it in action - and at E3 we're really looking forward to showing people multiplayer and how it works - hopefully that will show them why it's such a great feature and it's totally worth having.

"The benefit you're going to get out of being able to play online is going to help convince you of why it's worth it."

While Maxis is keeping its multiplayer cards close to its chest, we do know that the game will allow cities to interact with each other in sort of instances, with information constantly fed to the developer's servers. If you have a fire in your city, for example, and no fire coverage, another player's city may be able to come to the rescue.

And while your city does not continue to work while you're offline, it will still be able to interact with other cities that are in reduced ways.

People have their conspiracy theories over why we're doing it. But really, it's honest that the dev team feels like it really does add a lot to the game, and it's totally worth doing for that.

"The thing that's important for people to know is it really was driven by us as the dev team," Haber explained. "We feel it's a core feature to the game. It really makes the game richer. People have their conspiracy theories over why we're doing it. But really, it's honest that the dev team feels like it really does add a lot to the game, and it's totally worth doing for that."

He denied the decision had anything to do with combating piracy, too. "That's really the message we need to get out there and people need to understand. There are a lot of assumptions that people make and that's just how the internet is.

"It's a design choice on how to make the game feel more like a real city, right? And real cities don't exist in bubbles that nobody else has any influence in. City actions affect other cities, and other cities affect them.

"I live in the San Francisco Bay area. There are lots of little cities in there and they all interact with each other and all influence each other. Being able to recreate that momentum and feeling in SimCity is really important to the game."