Second Life, as the name might suggest, attempts to be much more than a game and instead presents itself as a second lifestyle. In Second Life, you play in a virtual would that is kinda like the real world, except for the fact that you can fly and teleport.
Kudos takes the basic SIMS theme of allowing you to live out the life of a virtual character. In Kudos you play as a 20 year old waiter. Your game develops as you make a series of important choices in life, ranging from trivial matters such as commuting to work, to much more important this like deciding to get married.