Pokemon Ruby is a great game, if repetitive. If Pokemon wants more success, there going to have try something original.
The great gameplay is still there, with good controls, and most everything seems to blend together very well. The game can take a long time to finish, and even then it's still pretty fun to go back and play through the game some more. There's pretty much always something to do in the game, until you have completely gone through the story line, beaten every trainer, gotten every item, every Pokemon, and raised them to the highest level possible. This can give any gamer quite a long game, which is always a good thing for any game. Too often are games going only for a few hours at a time, even though they have good plot, good graphics, good gameplay. Pokemon offers something for everyone to do... again.
The only real bad thing that is in this game is the fact that it is very repetitive, so gamers who have played all the old games before Ruby will find pretty much the same thing. The game is geared towards kids, but it's still pretty entertaining for adults, as long as you can get over the fact that you're playing a Pokemon game.
All in all, the game is great, just like the other games, and while repetitive, it is a very long and fulfilling game.