A sample from CheatCC‘s review:

The only real difference between MySims and any other party game is the implementation of a stat system. Each Sim character you can choose to play as has various strong points and weaknesses in areas like luck and strength, which will help your character gain an advantage in challenges that utilize these strengths. And if your character does well, they can even improve their stats. Although this is a good idea in theory, the different festival rounds are too short for the various stats to make any kind of difference, and I found that in most strength-based challenges, a +1 strength character will work just as well as a +3 strength character.