Its been years, but most of the stuff from Red and Blue are in the game, though there are quite a few extras added. Able to play as a girl, new area to sail to (I think it is called the Sevii Islands), and some pokemon from later generations show up too. Most of the actual gameplay is just the same, though there are a few things changed, such as the differences in type advantages from Gen 1 (notably Ghost-types), some changes to pokemon spawns (Moltres spawns somewhere on the Sevii Islands IIRC), and the levels of the Elites Four's pokemon being lower (though it reverts back once you go through it again). Overall, it has the same basic gameplay of the early games with a few extra bells and whistles, all of which frankly help extend the life of the game in my opinion. I especially loved the ability to challenge tougher versions of trainers again with some item (I can't remember). When I was younger, I definitely though it was a good experience.
captcha: black and white
Wrong generation.