Pros: Infinite replayability, new pokemon and features are great, replayable trainer battles.
Cons: Not compatible with the gbc games, not all pokemon can be caught in one game.
The bottom line: For 30$ this game will provide you with nearly infinite entertainment on the GBA, this game will also be very popular in the future.
First of all i will say this game has to be the best entertainment value on the GBA, and there are many ways to play this game as well, you can just play for the story, or you can play for the technical aspects of the game such as raising for perfect stats, breeding and raising pokemon. All in all i have gone 670 hours on the game (i have been playing since march 2003) and it sill provides tons of entertainment. I prefer to play for the technical aspects of this game as i am a computer science major and find this game technically very interesting, and its a lot of fun for me to play for the technical aspects of this game! Even if you could care less about how the game works you can still have tons of fun with this game, there are 200 pokemon availible in the game, about 180 pokemon in Pokemon Sapphire, and the same for Pokemon ruby, however like the previous games each version has their exclusive pokemon, so you must trade with the other version to "Catch them all".

The major downfall of this game is that it is not compatible with the previous versions such as red, blue, yellow, gold, silver and crystal. Basically all the GBC pokemon games are dead now, this may anger pokemon players who have been playing since day 1. This game is the first in the advanced series of pokemon (in other words be prepared to "start all over again"). The next games are pokemon fire red and leaf green, which will be compatible with pokemon sapphire and ruby, fire red and leaf green were released in japan on Jan. 29th 2004 and have not currently been released in the USA yet, however these games have sold over 20 million units already in japan. This is just to give a background on where the pokemon series is heading in the future. In other words, it is still alive and going strong.

This game has a very addictive concept as pokemon games have always had from the beginning, it is a progressive, role playing/strategy game. It is also text-heavy and it does mention on the package that you need to have basic reading and comprehension skills to be able to enjoy this game. I would not recommend this game for extremely young children (such as a 3 year old) due to the amount of text in it, it is a perfectly fine game for children, if you dont mind them playing their gba ALL the time.

The best improvement has been in the replayability of trainer battles, now a trainer will not just fight you once, but most trainers in the game you will be able to fight over and over, this makes raising and leveling up your team a lot eaiser and less tedious than before.