They don't matter. They're just short-lived packaging for what should be a fun, engaging experience. The best graphics in a game will be painfully obsolete within months, but true fun lives forever. You don't remember Centipede, Space Invaders and Missile Command because they were graphic triumphs. You remember them because they were fun, even addictive.
South Park has five levels, all with the same concept.
Find the other South Park kids, pick up weapons, kill something, kill a much larger version of the something, then run through a door. The weapons are actually quite diverse, ranging from the ever-present snowball, to dodgeballs and Nerf guns, to much stranger weapons like the Terrence and Philip dolls and the cow launcher. They're amusing, but tend to be scarce and underpowered. When you switch weapons, you switch to the South Park kid who uses that weapon, with all the associated taunts and quips. They're funny, though extremely overused.