And there’s a bit of a debate going in the industry now. You’ve got Gabe Newell from Valve on one side saying you’ve got to channel the player along the path of where you spent your money. Whereas Warren Spector’s take is that you’ve got to put your money everywhere and let them see it or not see it. I feel that to give the player the feeling that they’re in a real world, you have to do the broad approach where you make everything and you let them explore it, otherwise they can tell they’re on rails. Even if they’re in a big world, they can tell. It’s the difference between being on a ride at the fair and being at the fair itself.

Источник
Тима Шаффера можно цитировать бесконечно, он очень хорошо говорит и пишет. (Это не случайность, а талант, обуславливающий, по-моему его род деятельности.)

UPD: И еще про погружение:

When you’re not playing the game you don’t think of wanting to get back to play the game, but wanting to get back and hang out in that world.