Rockstar's RAGE engine is really something else. Like no other game, RDR gives me a sense that the world is filled with air, not just happening in some dry vacuum. The guys working on the engine clearly have a deep artistic passion for how light works, as well as an uncanny sense of the maths behind light diffraction and reflection.

I remember one time it started raining while I was at camp, the sky looked mostly clear, but then I looked straight up and sure enough a rain cloud had just blown in from behind me. A couple minutes later the rain stopped, I looked straight up again and the cloud had just blown past. I'd been playing this game for a couple years already and never noticed the rain comes from actual rain clouds.

I've always been a stop-and-smell-the-roses type who will just be still and gawk around for a while between jobs in the scenery is nice enough, but with RDR I've found myself suddenly stopping mid-mission just to watch a thunderstorm across the map for a while.