I can summarize this game with only a few words; a 2D Super Smash Bros with Sonic characters. At least that's what I've seen people compare this game to, and it probably would fit as a decent description, since it is ultimately a game about Sonic characters beating each other up.

The storyline is a little bit complex in areas; it features a robot named Emerl getting washed up on a beach near Sonic after Eggman decided it was useless. Sonic decides to train the robot to make it stronger, but it seems everyone wants Emerl for some reason, because of the fact that the robot is in fact a weapon known as the Gizoid. There are eight episodes devoted to this storyline in the Story Mode, where you can go through the character's stories, fight and most importantly, train Emerl.

There are a grand total of ten playable Sonic characters, with eight of them having their own episode in the Story Mode. Each of them play differently, but all have the general same controls. They can do the standard attacks such as punch and kick, but they can also use special attacks which are unique to their character. Sonic can use a spin-dash to summon wind to knock his opponents back, Tails uses his gadgets, Knuckles throws rocks and the more you fight opponents, the more Emerl will learn. He will gain abilities which you can customize in a menu later on to make him stronger, because when you start out with him, he's awfully slow.

The rules in battle are relatively simple; the one to score the most knockouts wins. Well, that's what it's like in some of the battles anyway. Some battles require you to get a certain amount of knockouts before your opponent, usually between three to ten knockouts in the Story Mode. Either way, it is not a traditional fighting game where, once the character's life meter is empty, they get knocked out and that's it. They'll keep coming back until a certain amount of knockouts has been achieved or the time has run out.

When you start in a battle and after you've been knocked out, you can choose the types of special attacks you use. You can use a ground attack on the floor, an air attack or plant a bomb. You can pick which you want to perform on the ground and in the air, with the third option enabling you to completely block that type of special attack. What's more, there's another meter above your health meter, which when you fill it up, enables you to knockout your enemy in one hit with a special attack.

Outside of the Story Mode, you can also access other modes available to you. Of course, there is the standard multiplayer option, enabling you to duke it out with some of your friends if they have this game on their Game Boy Advance. This is pretty fun.

But if you still want more single-player action, there's the Battle Mode where you can choose the character you want to use, and the character(s) you want to battle against, which is actually pretty fun as you have the freedom to choose any of the characters or the rules. There's also a Challenge Mode where you can battle with a certain character against various characters. Challenge Mode is generally something to pass the time and to bulk out the game just a little bit more. As you can expect, there's a Training Mode where you can get used to the controls/fighting methods of any of the characters, in any level of your choice. There are also mini-games that can be unlocked.

The graphics look pretty good. The character sprites once again use the Sonic Adventure style, and it looks great. The levels are in an isometric view, which makes it that little bit more interesting, and some of them have interesting designs. The music is different to what it was in the Advance trilogy – it's got more of a guitar sound to some of the tracks, which may appeal to some people, but not so much to others. I found the music decent. There are also voice-clips in this game from the original cast which sounds pretty excellent, fitting each character very well.

If you like the sound of a fast-paced, 2D Super Smash Bros with Sonic characters, you'll probably like this game, as it's all of that and more. It's fun to customize your own Emerl in this game, and its fun to just go around beating up on other Sonic characters. Definitely look into this one.