Yeah, the floor is out of perspective.
1. Try and keep all the tiles the same width, just make them shorter (distance-wise) as the go back farter.
2. The upside-down "V" tiles have got to go. They look funny. All tiles should be rhombus or trapezoid shaped (no, they should be the quadrilateral, not DJ Qualls shaped... wokka wokka...)
I guess, set a vanishing point at the top of the screen right in the center. The draw one line dividing the screen. Then, about 10-20 pixels away from that line, draw another line from top to bottom connecting with the vanishing point.
If you have any questions, PM me... I have a few examples I could show you.