This is a cool game. A very cool game. This game will entertain you, educate you, enlighten you, and maybe even make you cake. It's one of those games that unfolds as you play it, and making levers, stacks, shapes, long drops, slopes, etc. is very interesting. Especially on lime green.
Here's the link: Gravity Game called Sketch from Xavier Enigma.
Here's a video of my daughter Sadie playing this game. She is four and she loves it. She also likes airplanes, tutus, and poodles.