You're also greeted with the option to install an HD texture pack. The install is completely optional, though you'll want to make room for the 1.5 GB install since it makes a world of difference as far as presentation. Running on the improved Frostbite 2 engine, Battlefield 3 looks phenomenal, but takes a massive hit without the added textures. The downgrade in visuals doesn't affect gameplay, though the difference between the two is very noticeable. It's almost an SD versus HD sort of thing... you can still make out what's on the screen, but you lose a lot of detail.
Frostbite 2 isn't perfect, but it still delivers an amazing visual experience. For all its limitations, the single-player campaign still delivers some incredibly breathtaking moments. The first mission aboard a jet is breathtaking, as are a few other key areas. There's a lot going on, and DICE definitely delivers on the atmosphere. I did, however, have to make a few more adjustments to my screen's brightness. Battlefield 3 is a dark game, so you want to see as much as you can since enemies love to hide in shadows.
Audio is another knockout blow. I've always been a big fan of what DICE is able to pull off with its audio. I mean, I still remember playing Bad Company and thinking it was getting ready to rain outside my apartment. Battlefield 3 didn't fool me into phantom weather, but most of the little audio moments -- like insurgents assuring US forces they wouldn't be hurt after an earthquake -- managed to pull me into the experience.