Good concept. On the second level I didn't know what to do first, later I figured it out the the green package doesn't belong on the truck, but the button. It would've been easier to figure it out if the forklift pressed the button too, but when you'd leave it, the door would close.
The turn angle was a bit too sharp.
With a bit of work you could make a good puzzle out of this game.
(And one last thing, why is it 150 Megabytes? It doesn't seem like it should be. I know it doesn't depends on you, but it's quite a lot.)
And a good tip: Use zip instead of rar, some people don't use winrar or other programs like this.