As you start playing, you'll realize that the core loop is all about exploration and discovery. You'll be riding your horse through the desert, forests, and towns, taking in the sights and sounds, and stumbling upon all sorts of random events and encounters. It's crazy how much detail there is - you can interact with almost anyone, and the game remembers your choices, so you can't just go around being a jerk without consequences.
One of the most satisfying things about Red Dead Redemption is the gunplay - it's so smooth and responsive, you'll feel like a total boss taking down outlaws and rival gangs. And then there are the weird surprises, like stumbling upon a ghost train or a creepy abandoned mine - it's like the game is full of these cool little easter eggs just waiting to be found.