Sonic & Knuckles

Sonic & Knuckles (Sega, for Genesis, $69.99) There's nothing gaming aficionados like better than ''hidden'' levels-areas that can be reached only by luck, skill, or perseverance. This latest Sonic sequel has hidden levels up the wazoo. Not only can costar Knuckles (a kind of anteater) climb to places his hedgehog pal can't reach, but gamers can attach their old copies of Sonic 2 or Sonic 3 to the top of the cartridge and access levels in those games that didn't even exist before. It's a neat trick and one that saves Sonic & Knuckles from the sameness that's begun to afflict the series. A- -BS