Simply plain old school fun.
At first glance, Kid Chameleon may not be spectacular, but after playing through the game for a while, you begin to realize the sheer size and scope of the game. There are several power up suits that grant you different abilities, ranging from a miniature fly guy who can stick to walls, to driving a tank that can shoot. And even a nice hockey mask and axe ala Jason from Friday the 13th. The different power ups are awesome and add a lot to the game. They are wacky and quirky, and most importantly, downright fun.
Now, for the kicker. There's literally hundreds of levels for you to play through. I've played this game several times and NEVER came close to beating it. That's just how big the game is. Unfortunately, there is no save system, so you must start your progress over every time you shut your Sega off.
After a time, the game starts recycling elements of levels and baddies, but it doesn't detract from the sheer fun of the game.
In conclusion, you can't really go wrong with Kid Chameleon. It offers a ton of old school fun and is simply one of my favorite games ever made.