Some modern computer games are deep. Very deep. Mass Effect is like this. Far too deep for me. It is a role playing game where you have to interact with a whole bunch of people to get the job done. What happens to you do depends on what you do, and how you treat other people. This aspect of the game is very impressive. To someone watching the gameplay it looks very natural, and the feeling of actually being there talking to the other characters is very strong.
Number one son bought a copy of Mass Effect for the Xbox 360 last week, set himself up as a straightforward, honest and caring engineer, and went out to right a whole bunch of wrongs across the galaxy. He doesn't like the inventory management, but he does like the gunplay and the plot is quite compelling. I've seen the game on sale for less than 25 pounds, which represents fantastic value for something which could keep you busy for a rather long time.