Oooh, I just played a fantastic online RPG game called Grow. And after a fair number of tries I got it. Lots of fun. I'd hate to work it out first go as it will then seem easy to you. But the basic premise is to try and put the items into the world in the correct order to meet the goal/s.
And if you like, the hint is in the picture (I took a screen shot of the "winning" world).