scottie on 17 March 2010
It's a very hyped, game from an established franchise aimed at the kind of gamers who visit gaming websites and plan their purchases ahead of time.
Why should you be surprised that it has no legs?
If it makes you feel any better, it's still doing much better than the first on aligned launches basis, total sales
http://vgchartz.com/swlaunch.php?reg1=All&game1=Mass+Effect+-+X360[7635]®2=All&game2=Mass+Effect+2++-+X360[28815]®3=All&game3=&weeks=30
1.58 million to 1.23
