MM6 is one of my disappointments as a parent - I just cannot get my 12 year old son to play it. He says it's too hard. He's played through Space Rangers 2, King's Bounty, etc., but he just finds MM6 too difficult. My 9 year old feels the same way about Freedom Force.
In more MM related news, one of my best memories of these games is how there really wasn't much need to sleep as i recall, so I would go on very long exploration missions away from the town, only for one of my characters to suddenly go insane - it took me a long time to figure out that it was caused by lack of sleep...