Given people are commenting on the art, I thought I might chime in for a bit.
We went through a few style iterations right at the start of the project - mainly character proportions, which then would set the basis for the rest of the entire game. From lanky builds like, say, Gunstar Heroes over thicker Zelda-type proportions Konidias preferred the latter, and that is why not only the characters look like that, but subsequently everything from clothes to bushes to police cars evolved to suit that style.
Same thing for the character design itself. Again, a few proposals were made as the very starting point of everything, with completely different archetypes (I'm leaving it to you Konidias if you want to post that specific image), each changing the setting and feel of the game completely.
Sparrow, the main guy, has this blue-white-magenta color scheme going on which is reflected pretty much everywhere else - cool colors, pink, blue, white... That specific shade of magenta is reserved for sparrow though, and there's one particular location in the game where the colors are warmer. You'll find out, or at least feel it I hope. It's not jail, that's for sure.
I'd lie if I said that Superstar Saga wasn't an inspiration for the colors. SS has to have been the last Mario game with any sort of creativity in it, visual or otherwise, and I remember being really impressed by the direction the artist took for the main illustrations - even changing the basic hues of the characters (Luigi is turquoise/fresh blue). I think if a guy tried that at today's Nintendo they'd get fired on the spot.
Looking at the game's progress, I still see the colors do need some tweaking, but that's quickly done as the game comes together. At the moment things still are a bit WIP, at least on my side here. But I'm very glad people like it, and I hope it's gonna become even better!