I just thought I'd join the challange, might look unfinished but i worked a while on it.
i agree with the others, it needs more work. if you yourself say it looks unfinished, then it must be.
It looks way too bland. Right now it just looks and feels like its the entrance to a japanese garden.
Only because of the background i might know that its an amusement park, but even then, i only knew what those things in the background are because i know what the challenge is.
You should put up a flashy sign, add some balloons, people, fireworks!
Whatever works to get that amusement park feeling!
Looks good, but you really out to finish it.