Fantastic Contraption is a 2-d physics based game in which you build a machine to get the goal piece (red) into the goal (red area). Each level has an almost unlimited number of solutions. Here are some of mine:

• OmniPlow solves the level "Awash." Most solutions to this level involve letting some of the balls roll backwards over the top of the vehicle, but OmniPlow pushes every single one up the hill and off to the right.
• Minnow6 takes the exact opposite tack to OmniPlow, letting almost everything flow downhill to the left. I set out to make the smallest possible car that would solve the level. There are ways to solve the level using fewer pieces (by catapulting the goal piece over everything) but this is the smallest solution I know of that uses the car strategy, and it is perhaps my favorite design. Note that the red drive wheel is powered only by friction with the top wheels.
• Square Wheels is a simple solution to the level "Up The Stairs." This level is very difficult to win with a smooth-wheeled "car," but adding spikes makes it no problem.
• Jellyfish is a silly solution to "Up the Stairs" that barely works (but it does work).
• Whip Cracker solves "Up the Stairs," Indiana Jones style.
• 3 piece solves "Up the Stairs" with just 3 pieces. It's inspired by Whip Cracker. The long tail is necessary to prevent the vehicle from flipping over backwards.
• Horde solves the level "Big Ball" by sending a horde of tiny vehicles under it to push it out of the way. It takes a while but wins in the end.
• bigball5 solves the level "Big Ball" with five pieces. It's possible to do it in 4.
• unpoweredbigball solves the level "Big Ball" without using any powered wheels. It's inspired by someone else's solution to "U-Turn."
• Trike1 solves the level "Big Ball" by lifting the ball out of the way. It's the smallest solution I know of (6 piece) that does that.
• dunder4piece solves the level "Down Under" with four pieces. A three-piece solution may be possible.
• 2 pieces solves the level "Full Up" with 2 pieces. It was very tricky to get this one to work.
• 3 Wheels is a solution to the level "U-Turn." There's nothing too special about this one but it gets the job done.
• SimpleGah solves the level "On a Roll" using only two pieces.
• One Piece solves the level "Mind the Gap" using just one piece.
• One Stick solves the level "Reach Up" using just one piece.
• Junk Plow solves the level "Junkyard" by pushing every piece off to the right, similar to OmniPlow.
• Junkyard3 is another solution to "Junkyard" along the lines of my 3-piece "Up the Stairs" solution.
• Fishing Pole solves the level "The Wall" with only two pieces.
• higher2pc solves the level "Higher" with only two pieces.
• mars1 solves the level "Mission to Mars" with a single piece. I confess that this was not my idea, but it did take some tweaking to work properly.
• handling5 solves the level "Handling" with just 5 pieces.
• Tethercar solves the level "Unpossible" fairly simply. I wish there was some way to eliminate the need for a chain so that the level could be solved in a small number of pieces.
• Tube 3 Piece solves the level "Tube" in 3 pieces. Once again, the idea for this design was not mine, but it did take a lot of tweaking to get to work.
• 10 piece b&f solves the level "Backwards and Forwards" in 10 pieces.
• 4 piece hump solves the level "Over the Hump" with four pieces.
• 3 piece hump solves the level "Over the Hump" with three pieces.
• paddlewheel2 solves the level "Four Balls" with 6 pieces.