Sonic advance 3 is definately the best on the GBA. The first game was quite fun, but the pace was very slow for a 2d sonic game. The second's level design wasnt great, especially sky canyon with its many leaps of faith. This third outing is the all-new sonic you've been waiting for. Something you will notice is that it is far more challenging than the previous games. It starts out alright, but the final stages are actually quite tough, and may take many attempts. However, the biggest change of all is the secondary character that follows you. This adds some extra depth to the game, as different character combinations will suit different styles. For example, Sonic and Amy are great for those who want to go on the offensive, while Tails and Knuckles' airbourne abilities will come in handy for beginners. Unfortunately, the AI isnt great, and your partner can get in the way at times. Sometimes you will have to jump on a moving platform. If your partner jumps on it first, causing it to move away, you will fall to your death, which will frustrate many a gamer. The game structure has had an overhaul. Rather than continuing straight to the next level, you enter one of seven hub worlds, each with three levels, which can be tackled in any order. What this means is if one stage is proving particularly taxing, you can try another and come back at a later stage. A diverting side quest is to find the seven hidden chao in each world. Finding all seven will make a key apear in a stage, which will enable you to unlock a bonus stage, completion of which will net you a Chaos emerald. Getting all seven emeralds will unlock the final stage. Trust me, it will take yo a while. I recomend this game for anyone after a good platformer. It is the definitive Sonic handheld game.