We are having some REALLY huge game worlds appearing nowadays!

-GTA5 probaly takes 20 min of non stop driving (without crashing) to get from one side of the map to another

-We are told the Witcher 3 will be 50% larger than GTA5!

-Assassins Creed unity, though a pretend open world game, has a huge world

-minecraft Xbox One/PS4/PC has a virtually unlimited world

Not only are these game worlds huge, but you can go inside buildings, underwater, and in GTA5's case, in the air.

Will we see game worlds this gen 2X-4X larger than GTA5?? I think yes.

As games appear on this gen only devs will allow players to install massive amounts of content on the consoles HD. I think we will start seeing HUGE games within the next year or two!

They're definitely getting bigger. We're definitely headed for some exciting times in the Open World genre.

Just imagine, Game Worlds as big as the real world

Size is limited by only three factors.

1) Complexity
2) Development time
3) Cost vs projected profit.

Also, I think the 20 minute estimate for GTA5 sounds a bit off, I've done an end to end run from airport to north beach in under 7 minutes.

I'm proud to have the "Drive on all roads" achievement for TDU.

Look at Xenoblade Chronicles X too. I can't wait till people compare the mass of that world to other games today.

Daggerfall is twice the size of the entire UK.

The Witcher 3 is supposedly at least twice as big as Skyrim. The problem with open world games is that the bigger they, the less varied and deep they will be, developers have to resort to cheap tricks to fill the world and this shows in the finished product. Locations looks the same, very few enemies compared to the world's size, poor AI with short range, mottled and muddy textures everywhere, massive amounts of bugs and bland side quests everywhere. Open world games are hard to do right.

never heared of that game

I...erm...erm...

*faints*

Breathe in...breathe out...you can do this Coney...

It's quite a big game. 400 square kilometres, or around 3-4x the size of GTA V, if not more. So yeah, pretty big! 

And as for your question; the only thing holding the game size back now is how feasible and how practical it is to do; as opposed to hardware.

Never heard of Xenoblade Chronicles X....? Look at this. You'll thank me later.

https://www.youtube.com/watch?v=AvpNXhzscjQ