Sonic Adventure 2, like most games in the series, is renowned for its relatively simple game play. Unlike most other Sonic games, however, this one has several different features that may need to be elaborated.
General Gameplay[edit]
The game is split into two separate, parallel storylines: The "Hero" Side story, and the "Dark" Side story. Though each storyline is played using different characters, they have essentially the same abilities and the levels are roughly analogous so that neither side is more difficult than the other. To complete the entire game, a player needs to go through both, though order does not matter. The levels in each storyline are split into one of three categories, corresponding to each of the classes of characters: Speed, Treasure Hunting, and Shooting.
Speed Levels[edit]
These are fast-paced, high intensity levels run through by Sonic and Shadow. The point of these levels is to reach the "GOAL" ring located at the end, which usually represents some point in the storyline (IE, exiting the jungle island before it explodes.) To get a good ranking on a Speed level, it is recommended to gather as many rings as possible and fight as few enemies as are necessary. Time plays a large factor in the computation of these scores, so the points obtained from destroying enemies is often not enough to make up for the time wasted defeating them. Another way to get points in these levels is through the use of tricks while grinding. When a player reaches the end of the grind rail, by pressing either 
or 
at the right moment, they will perform a trick worth a varying amount of points depending on their proximity to the end of the rail. Sometimes these tricks are required to progress.
Treasure Hunting Levels[edit]
These levels tend to be large, sprawling landscapes (with the exception of the first level in both storylines.) that spread out in all directions for a great distance. Some are rather complex mazes, especially later on. The goal is to find 3 items (almost always shards of the Master Emerald, though in a few cases other objects such as Keys.) as fast as possible using Knuckles and Rouge. There are also monitors located around the levels that give hints to the location of the next shard. One can use up to 3 hints, and often the third hint is a dead giveaway of the item's location. The drawback to using these monitors is that they drastically lower the point bonus gained when a player does actually find the item in question. Completely ignoring the monitors is not wise either, however; the point value will also decrease if a player takes too long to find one item. Strategic use of the hint monitors plays a vital role in getting the best ranks on Treasure Hunting Missions.
Another useful feature when treasure hunting is the "radar" located at the bottom of the screen. This radar acts as a hot/cold reaction to the items in the level. When a player is no where near the item, the pictures will be grayed out. As the player draws closer, the color will shift from gray to green to yellow to red, and finally when the player is right on top of it an exclamation point will appear over the character's head (only in the GameCube version.) The radar only works on the primary item, however. The secondary (or tertiary) items that are being hunted down do not react at all, even if the character is looking right at it.
Shooting Levels[edit]
The shooting levels involve locating a "GOAL" ring at the end of a level. Unlike the speed levels, however, time is not the deciding factor in point scoring. The best way to get large numbers of points in a shooting stage is to always lock on to as many enemies at one time as possible. Each mech's targeting laser starts out as a deep red, and as the button is held down, it slowly fades and eventually turns blue. When this happens, the targeting system is about to go offline, so it is recommended that the player release the targeting button before this point. Also, the targeting system allows the shooting characters to lock on to and hit item boxes from very far away, making it much easier to gain rings. The mechs are also much, much slower than the speed character, have shorter jumps, and are generally less maneuverable. This makes performing delicate procedures in them far more difficult. In these situations, it is usually better to "Shape" the environment in your favor, by destroying certain boxes and leaving others, or by creative use of the hover jets (which are obtained later on in the game as an upgrade.) Another difference between the shooters and the other characters is that the mechbound characters have health bars, allowing them to take many hits from enemies with zero rings. The other characters will die under such conditions.