Very frustrating! Each design has some kind of a challenge and some of them have a very limited set of options. People don't follow the challenge at all and still win (i.e.: this challenge called for blue options on designing a bedroom for a little boy, the blue colored options were limited and expensive, so you had to spend a lot of in game resources. People who opted for the cheaper, pink, yellow and white colored options won the challenge in high ranking positions). It's a money farming game!