Practice...
I'm giving you a 5/10 because I have been (may still be) where you are in flash game development. I am making one currently, and I have run into so many problems, and searched through so many tutorials, that my game keeps getting better and better. It's not the best yet, but that is what I'm striving for, and what I think you need to strive for if you want a better rating than 1.7...
You settled for half-ass, and in my opinion you should search around the net for some tutorials, (even here on newgrounds) they will surely help you, and most of them explain everything that is in the scripts. You have glitches out the wazoo in every "level", no enemies, and your character is halfway through the ground. That alone could be fixed if you saw even 1 tut.
I wish you luck in the future if you do decide to continue working on games.