A Reasonable Start...

The games dynamics are slightly flawed; you need the movements to be smoother as they would be in a hot air balloon, and not jumpey as though I was controlling a robot.

The balloon seemed to glitch a little bit as I pressed the right key and the balloon fell; as though it was flickering, though not a huge impact on the game as I didn't hit anything.

I'm not impressed that the game just finishes on a white screen with a continous loop of infuriating music - I should turn my speakers off while I write this :P

The game has a solid base, but you will need to improve the animations and add in more objects to get out the way off, as mentioned below by Rupe-The-Dupe. It's a good start; but needs much improvement to become a great one, to rival the likes of the original Helicopter game.

why did you upload this?

it's not really playable at all. Finish the game and come back.

well,

Its okay. The concept itself is a little basic but I'm sure you can spice it up with a few things, low flying aircraft, construction sites with wildly swinging cranes etc...
The control system is good. The graphics are ok, but there's no reason not to improve them if you have time. The music is novel, but will grind on a player after a while, so a music on/off switch is a must. (M button maybe)

All in all it's ok, tidy it up nicely for the full release and you'll do quite well. Rating 5/10, but my personal philosophy is to reject all incomplete submissions, regardless of how good they are, so bagel on the score I'm afraid.

not bad

you should have made it longer and call it "UP"

I suggest

You finish it before you upload it.