The game is great, but mostly for the boss combat and unique stage design. The "Hub" overworld with the buried money, Lovikov's Balls, and various all over the map you have to visit is pretty dull. There's nothing to do but go from place to place to place and earn money. It would be better if there were actually something going on in the city, like random assassins trying to take you out for your rank or something, or perhaps a robot policeman that wonders around at mercilessly attacks you because you're a killer. Just something to liven up the town. You should be able to kill people on the streets, too, just because you should be able to.
However, after you collect the random things found in dumpsters, the balls, the buried money, and figure out how not to flip your bike over, you'll spend a whole lot less time in the hub city, and more time doing the jobs, missions, and actual stages, and the game immediately gets better. Also, getting the "Dash" ability helps, since you can dash a whole lot faster than you can run.