Oh boy, that took some serious tinkering, but I managed a nice, simple solution for Down Under 
I may post some solutions later, but this reminds me of an age old Sierra game I played a long time ago called The Incredible Machine. Granted, that game was a lot more varied with many more potential objectives, but I’d be surprised if it wasn’t er… inspired by it (given the title). Anyone who likes this game may ant to see if they can find it used at Bookmans or something (assuming they can get it to run) it’s a fun game.
Okay, you win. 
How I got past Four Balls:
…I created a static ramp, then suspended counter-clockwise wheels above with paddles attached to push the target balls along…
Link
and
Down Under
Full-Up: Snake! Snake! It’s a snake!
This is very addictive, behold the traction monster on Awash
Finally!
Ha!, check this handling!
Oops, wrong link, here’s the right one
I took this design: Stomping Elephant and made an alteration: Backstroke Elephant
Both of these take about 10 minutes to complete.
Aha!, I conquered Back and Forth, it’s an awful mess but it works. :o
Now let’s see that last one…
Behold The Unicycle. 
That’s friggin’ awesome.
I ended up solving this one with a conveyor belt.
I saw a lot of solutions more elegant than mine for the Big Ball. I basically just built a bulldozer to pick the ball up and slide the brick under it.
And that unicycle is incredible!
The fact that I am posting this at 5:15 AM says alot about how long I’ve been playing with this. Great find!
Four Balls was a bitch. But I finally got it.
Good lord. I thought I’d never get those four balls up there. But in the end, I’m quite proud of my solution, especially the accelerator at the beginning (damn balls just kept piling up).