I just started trying to do it. I have a couple of ideas. I'm pretty sure that it's possible. If I do it I'll post my solution.

i really like the contraptions that involve multiple machines to accomplish the goal, especially when it makes the process much more complicated than need be :) http://FantasticContraption.com/?designId=65299

Elegant Handling

Graceful, no?

Here's one for "Mission to Mars"
http://FantasticContraption.com/?designId=67730

:D

There's now a new update to the game, see this link: http://fantasticcontraption.com/forum/viewtopic.php?f=3&t=104

Yay finally solved "Unpossible"

Man, Down Under really started to get me after a while.

http://FantasticContraption.com/?designId=73877

Hehe never thought it would work but it did :)

Here's the closest I can get to completing Pokey's Tube Challenge (See post on July 24).

http://fantasticcontraption.com/?designId=74509

Just a little more tweaking and I think I can get it.

My solution to Up The Hump:

Awash 51.49 seconds over the top

Here's my Possible

My solution to Big Ball:

Flyer revised to solve:

http://FantasticContraption.com/?designId=80715

Finaly accomplished Unpossible, I call it DrawBridge:
http://FantasticContraption.com/?designId=82040

http://FantasticContraption.com/?designId=85203

mission to mars succes an easily made ay take a while though

http://FantasticContraption.com/?designId=85203

K check this out,I was experimenting with the flyer idea using two wheels instead of one and the right wheel starting doing funny stuff.

Can anyone explain?

http://FantasticContraption.com/?designId=86549

Flying(almost) Letter:
http://FantasticContraption.com/?designId=86827

eternaljwh, where did you get that disign? I made one that is exactly like that one.

Ha!!!
I've created the ultimate flyer lol.
This one really does make it to Mars.

http://FantasticContraption.com/?designId=90102

Watch closely now.

Finally beat Unpossible:

Rube Goldberg would be proud.

Slingshot solution for Big Ball

http://FantasticContraption.com/?designId=98435

I hade a contraption that used legs to walk up the stairs. Or crawled, rather. However, here's a more elegant solution: http://FantasticContraption.com/?designId=103015

I like this solution to "Handling.

http://FantasticContraption.com/?designId=105785

Anyone know what the fewest number of pieces needed for a green solution to each level is? Here's my attempts at the first three levels using green solutions with as few components as possible:

1: http://FantasticContraption.com/?designId=60079

2:
http://FantasticContraption.com/?designId=60265

3:
http://FantasticContraption.com/?designId=60337

TheTelf, you don't need any pieces to beat the first level. Just move the red wheel to the right edge of the editing area.

My solution to 'right beneath'.. or something like that
http://FantasticContraption.com/?designId=113553

Four Balls in under ten seconds.

http://FantasticContraption.com/?designId=113941

This was easier than I thought, but gets the job done on "Back and Forth"

http://FantasticContraption.com/?designId=118448

Cleared the wall in 6,5 seconds.
A truck

http://FantasticContraption.com/?designId=123348

Jumpy truck

http://FantasticContraption.com/?designId=123420

This is full-up, using almost the same truck and the big ball on top as a bridge

http://FantasticContraption.com/?designId=123574

Unpossible
http://FantasticContraption.com/?designId=95463

Junkyard Bulldozer
http://FantasticContraption.com/?designId=60833

The Wall vs. Bulldozer 2
http://FantasticContraption.com/?designId=60852

Tube
http://FantasticContraption.com/?designId=83775

Back and Forth
http://FantasticContraption.com/?designId=95415

back and forth, one small simple machine

http://FantasticContraption.com/?designId=135329

@ TheTelf

Re: Level 1 Greenest (Fewest Pieces) Solution

Just move the pink circle. No additional pieces needed.

http://fantasticcontraption.com/?designId=141725

@ TheTelf

I was able to reduce your "Green 3" by two pieces.

http://fantasticcontraption.com/?designId=141848

My ridiculously long winded solution to Back and Forth. Took 3 hours but was so worth it. http://FantasticContraption.com/?designId=143518

Solution for "Down Under"

Stay in place with a claw:

http://FantasticContraption.com/?designId=144348

Not to be a downer, but I think Pokey's tube challenge might just be impossible....

much more elegant Mission to Mars solution...

http://FantasticContraption.com/?designId=152334

Praise me. PRAISE ME!!!

/invader zim

up the stairs solution with a trebucher

http://FantasticContraption.com/?designId=155981

am I seeing things, or is the red ball going straight through solid wood???

http://fantasticcontraption.com/?designId=16157

I was modifing my mission to mars solution
http://FantasticContraption.com/?designId=167658
And I Ended up with this(look how the chain just passes through the green)
http://FantasticContraption.com/?designId=168300

an easier way than tracks but does the same idea works for most levels

http://FantasticContraption.com/?designId=171038

I have made a "no pieces used" solution to AROUND THE BEND, check it out:

http://FantasticContraption.com/?designId=0

here is a four piece green on Higher, enjoy:

http://FantasticContraption.com/?designId=176404

here is a Green impossible! (not mine at all)

http://FantasticContraption.com/?designId=15077

'Handling' has got to be the level with the most diversified solutions I've seen so far.

And here's mine. :)

http://FantasticContraption.com/?designId=193260

I made 'the flyer' work

http://FantasticContraption.com/?designId=216037

http://FantasticContraption.com/?designId=216772
it uses no parts on around the bend
not mine

http://FantasticContraption.com/?designId=218139 my pro solution for handling

http://FantasticContraption.com/?designId=233661

i thought this was an interesting way to beat mission to mars

http://FantasticContraption.com/?designId=240294

here is my solution to ambush. i cant believe it worked.

http://FantasticContraption.com/?designId=255701

I think I like my solution to the Handling..
http://fantasticcontraption.com/?designId=263116

@LSN

Woohoo... I have finally solved... THE TUBE!
http://FantasticContraption.com/?designId=261435

It uses gravity to help it keep itself wedged between the green walls.

I've also found that the chain can break and/or go through the green if there's enough weight.

I'm still having a ton of trouble trying to win the Unpossible level... I built a catapult, but not sure how to get it to swing around correctly... *brainstorms*...

My latest attempt at Unpossible:
http://FantasticContraption.com/?designId=268606

So close.. yet so far, far away...

See what I did for Mission To Mars :)

My Four Balls
http://FantasticContraption.com/?designId=283897

Junkyard:
http://FantasticContraption.com/?designId=284122
The Wall:
http://FantasticContraption.com/?designId=284215

OH MAN! This took me so long, fiddling with the length of the chain. But I did it:

http://FantasticContraption.com/?designId=284182

It's for Handling.

Anyone else notice that sometimes the same contraption will work one go-around and not the next?

That previous entry of mine definitely seems like a fluke. It only works 1 out of about every 5 or 6 times.

This one, while ugly, works much better.

http://FantasticContraption.com/?designId=288300

Thanks for the easy bridge tip, whoever that was.

Green Four Balls
I didn't see anyone else find a green solution for Four Balls, but then I didn't try all the links since my browser seems to hang frequently viewing other people's links :-(
http://FantasticContraption.com/?designId=292486

I have a dog in this game!

http://FantasticContraption.com/?designId=314528

I just thought that this was really cool:
http://FantasticContraption.com/?designId=317240

A four balls solution. Uses a cart, ramp, and a strange box.

http://FantasticContraption.com/?designId=336556

Looking at all these solutions, I realize most of my designs were rather unnecessary. But that's not the point; this game is fun, and had I any money, I'd get it in a heartbeat.

Well, I have a challenge for you all:
Can anyone build a faster drill?

Here's mine:
http://FantasticContraption.com/?designId=342417

Here's my unnecessarily complex solution to the Tube

http://FantasticContraption.com/?designId=346015

look that something really strange happened!!

http://FantasticContraption.com/?designId=327230

I made this on my many attempts on Mission to Mars, at first it didn't work, so I skipped that level, then I came back to it and made this:

http://FantasticContraption.com/?designId=354117

Solution to Back and Forth
http://FantasticContraption.com/?designId=361452

This is a solution that I made for "Rolling Away":

http://FantasticContraption.com/?designId=362381

http://FantasticContraption.com/?designId=374414

Big ball, and kinda fast.

my design for the level mission to mars

this is a very useful design, simple, powerful.

the best way to make a "tank" like motion on this
http://FantasticContraption.com/?designId=378818

I made two more designs:

http://FantasticContraption.com/?designId=376469
http://FantasticContraption.com/?designId=376690

The first one is for Reach Up, and the second one is for Mission to Mars.

I quite like my solution for unpossible

http://FantasticContraption.com/?designId=387485

it fast too =)

@Ainegue: I know that the level itself is solvable, but at the bottom of Page 1 of comments here, the user Pokey poses a challenge that I think is pretty impossible, or very darn near it:

POKEY'S TUBE CHALLENGE
----------------------

Having fun creating ingenious fantastic contraptions? Why not test your skills on Pokey's Tube Challenge!?

Here's the challenge: Complete the "Tube" stage by bringing the red ball around the outside of the tube. Your contraption can do whatever it needs to do, but the red ball must travel out the bottom of the tube, up around the side and back down through the top of the tube.

Who ever can do this gets an e-high five!

Hi Guys This Is My First Ever Post On The Site After Months Of Using It I Would Like To Ask If Any One Can Clear The Wall On The Wall Level This Is My Best

http://FantasticContraption.com/?designId=395119

here's my level:

http://FantasticContraption.com/?levelId=4066

How do you do Up the Hump? It appears to be impossible.

Sorry for double post, but my design is simple. Just two wheels, a triangle, and a line!
http://FantasticContraption.com/?designId=403979

Here is my down under solution

http://FantasticContraption.com/?designId=406853

@Grace
Up the Hump
http://FantasticContraption.com/?designId=409208
http://FantasticContraption.com/?designId=409455

You know, I can never get tired of this game.

They should make something like Robot battles, or Robot Soccer, or something, so people could compete their Contraptions against eachother. That would be so cool...

This is my "green" design for full-up. I'd love to see someone beat it.
http://FantasticContraption.com/?designId=417578

I think that this is just skill...

http://FantasticContraption.com/?designId=423944

thats not green

http://FantasticContraption.com/?designId=435097

awash
fast 22 seconds

This is a conveyor belt I made for the four balls.

http://FantasticContraption.com/?designId=435181

perfect mission to mars...

http://FantasticContraption.com/?designId=438717

this tank thing made me really nervous! lol enjoy!

http://FantasticContraption.com/?designId=442161

http://FantasticContraption.com/?designId=443181

This is my contraption for unpossible using as few pieces as possible. I did with only 23 pieces.

Self Building Bridge
http://FantasticContraption.com/?designId=446069

Wasnt meant to happen lol but it did

up the hump

Unpossible, 3 machines. awesome

http://FantasticContraption.com/?designId=453413