i must say nice effort.
I couldn't do that much work in a day XD
the bg is alright.
The characther the girl is perhaps look better tha the guy.
A bit work on the perpective for the guy, but it's not a biggy.
the coloring perhaps can be improve using less ???
Having the shadows simplified >.< Uh i don't know how to say this >.<
Perhaps looking into a vector colored works will give u an idea ^_^
Nonetheless amazing effort ^_^
Keep it up.