There is a Playboy bunny rabbit logo on the tail of one of your planes. If you're in Mubai you don't know, but it's a magazine of naked women. You probably do not want that on a professional site!
Speaking of that, depending on what you want to show off, it might or might not be an issue that the graphics all on the front page came from somewhere else. People can find clip art of space shuttles and hot air balloons anyway. If you want to show off your programming skill then great, but ask programmers.
(It seems kind of easy to break because you can resize the window and sink the shuttle into the ground. The end position looks stuck...I can't imagine this works on the phone.)
You might want to have a more basic fallback page by default and call this your "experiment" that people who want to see click to. Then you can be like Google where you are in beta forever, and never be responsible if its broken.
"Is the use of fonts appropriate? What kind of fonts should I change to if these ain't right?"
"From a UX prespective, is this kind of concept user friendly"
Confusing to scroll down, when the thing you're looking at is going up. I couldn't tell you for sure that it couldn't be made really tight or not. All things equal it's good to dare to be different, I'd worry more about people knowing what to click on, and using clip art on a page saying you're a designer as a first impression.
When you click through to that part of the things you made, the numbers are wrong and not in order. And it's hard to find the button to close it once you have it up. If you're flying by things why not fly through the art itself, or over it?
The portfolio design is one question but then it's a portfolio that is kind of hard to get to. You have the skill with software so a little bit could make a big difference I bet. So maybe if you look at things like the restaurant:
I'm not even going to talk about "new branch address here" (you need to fix that for a portfolio)! But like I said about clip art before you should ask if everything you make is out of clip art then where is your control? If the "75 years of Excellence" scroll has Excellence too close to the right and the 75 is too close to the left or the scroll is too small, why don't you control that? If the color of the red in the company logo isn't matching why don't you control that?
Someone paying you to do work expects you to control this and you should show you can if this is a portfolio about you being able to design. Unless you are going to not listen and just do programming work, then ignore me because you will be rich and it won't matter.