Super Mario
The game's plot begins when Mario has a dream. In it, he climbs a huge staircase to a mysterious door. Upon opening it, he finds an entire new world spread out before him. A voice calls out to him, telling him that he's reached the world of Subcon and that they need him to free them from the evil Wart. The next day, Mario and his friends go out on a picnic. Amazingly, they discover a cave with a staircase to a door, just like in Mario's dream. Then, even more amazingly, they find the world of Subcon behind the door, exactly as Mario had seen it the night before.
The game plays a lot like any other Mario platformer. You go from left to right (normally) and collect items to help you in your quest. However, there are a number of differences that make it a very unique game in the Mario series. First of all, before each stage even begins, you have the option to choose between four different characters. They are: Mario, who has sort of average but well-balanced abilities, Luigi, who makes huge jumps but is sort of weak, Toad, who can't jump very well but is incredibly strong, and the Princess, who can't jump that well and isn't strong at all, but has the ability to float through the air for short periods of time. Picking different characters can have a strong effect on how well you do in each stage, but it's possible to beat any level with any character.
Also, unlike in other Mario games, in this game you don't defeat enemies by jumping on them. Instead, you need to jump on top of them and throw them at other enemies. Also, you can pull items out of the ground instead of hitting blocks to get them. And to find coins, you need to use a magic potion to take you to the Sub-World where you can pull them out of the ground. But instead of giving you extra lives for every one you collect, you use them to gain opportunities to win extra lives at the end of every stage at a slot machine. And finally, every single character has a life meter. There are no special powerups in this game, instead you must simply increase the length of your life meter in every stage to make it easier to survive. Of course, this may or may not be a welcome change, depending on your point of view.
There are also some things that were changed specifically for this version of the game. First of all, you'll notice some new enemies around the different stages. However, most of them are just larger versions of normal enemies. There is one new boss character though, but that isn't too much of a huge difference. Also, certain stages have been redesigned, and these changes are very noticeable. For example, the first room of the first stage has been given an almost complete change. Instead of beginning with a free-fall down to a hill, you instead walk down a cloud staircase to a series of platforms and one of the game's new gigantic enemies near the bottom. A lot of these changes aren't as noticeable, but they still might stick out to anyone who is a veteran of the old games.
The game's graphics simply look awesome. The world of Subcon is a lush landscape filled with all sorts of wonderful sights. All of the characters and items animate perfectly, with one little exception. When an enemy spins around, like after you throw them for instance, they tend to look a little blurry and distorted. This might annoy you a little, but it's not that big of a glitch. Overall the game looks wonderful.
The game's sound is also marvelous. You'll recognize all of the songs from the old game, though they've now been remixed to take advantage of the GBA's power. The sound effects are also wonderful. However, the developers have also decided to add voice samples to the game, and that can become really annoying. It's nice to hear characters like Mario and Luigi talk every once in a while, but it seems like they say something after every little action that they perform in this game. Also, the voices that have been given to most of the bosses are a completely out of place. I don't recall Birdo sounding anything like she does in this game in any of her other roles, but in this game she comes out with overly dramatic lines like "I'LL REMEMBER THIS!!!" and "HOW COULD YOU?!" that don't really fit into her character. It's really just something that will get on the nerves of anyone who's been playing Mario games for a while. They really should have just left the voice samples out of this game.
Also, Mario Advance contains a version of the classic arcade game Mario Bros. that you can play with up to three other people. It can be quite a bit of fun with other players to share the fun, and you don't even need multiple copies of the game to play with them. At the time this was released, including this version of Mario Bros. hadn't become a stale gimmick on the GBA yet, and it really does seem to be a lot of fun to this day.