In retrospect, this game had everything: style AND substance!
Premise of the game? Put on some skates and start to paint the town. But the game doesn't endorse any sort of graffiti. It doesn't! The disclaimer says so!
When I was first playing through Jet Grind Radio and skating my way around Shibuya-cho (because apparently, every major landmark of Japan becomes unique as soon as you add one character to it...), listening to the Pirate DJ "Professor K" from Tokyo-to (see what I mean?), I didn't truly appreciate what I was playing. Sure, the cell-shading, revolutionary for its time, was kind of cool, but I couldn't truly appreciate something that Jet Grind Radio executed SO very well: level design. Everywhere, there were unique locales to grind around. Enemies had enough variety (there were even "special agent" enemies that had special powers...ridiculous, I know) so that you were never truly bored. In short, Sega actually took the time to ensure their game would be FUN...which is unfortunately rare.
The graffiti mechanic was fun at first, but was hampered by a design choice. In order to get a full graffiti tag, you had to stand in front of the mural, executing the on-screen commands. Meanwhile, thanks to the dynamic camera angles, you could see nearby enemies rushing you. That meant that performing graffiti was a function of you having enemies chase you, get them as far from the wall as possible, then skate back and pray you got the enemy far enough away. Otherwise, in the middle of your graffiti, the enemy could just conk you on the head. Sure, you could cancel at any time, but once again, it gives this "staggered" feeling that I'm coming back to. Considering that escaping the various enemy types was very action-packed, this choice was rather strange. If it were me, I would have blended the graffiti and action...but it's not a major hit against the game, since I'm sure at the time, that was easier said than done. Still, it would be cool if the action paused, or at least slowed down, while you were doing graffiti. Maybe extra style points for being able to perform a trick (front flip) while doing the graffiti, even though you would get less time for each move? Maybe you get less time to do the moves the more enemies that are nearby, but it doesn't mean they can just pause the action. That way, you can run and tag at the same time. That's the most fun anyway!
I mentioned cell-shading before. It gave the whole game a VERY unique feel. Combine that with some very appropriate J-....I don't know how to classify it. J-Hip Hop? J-Pop? It was J-something good.
I mentioned that I'm reviewing this game because it deserves a sequel. It actually did get a sequel...Jet Set Radio Future for the XBox, but I hardly count that. That game, also made by Sega, tried to make Jet Grind Radio more of a sandbox. While that could conceivably work, the action was VERY SLOW, and the level design was just plain confusing. I always knew where I needed to go in Jet Grind Radio. If they're going to do a sequel, they should do a TRUE sequel. Mature its look, make it more-action packed and smooth, more stylish, and bring back the great level-design.
Overally, Jet Grind Radio was a great game (some issues aside), innovative and definitely worth playing. Just ignore the generic "evil corporation trying to take over the world" plot.