A speed run of Demon's Souls only takes 1 hour, same for Dark Souls. I guess they are the worst games in the history of gaming.
Even if all you do is get each area down to 30% clear and do the DUP show downs you will definitely take at least 10 hours.
MGS GZ might have a lot of replay value, but at 2 hours you have to replay it 5 times to equal a 70% completion rate play through of ISS. And then there's the 5 hours of papertrail added on to the main story, so 15 hours for a fairly story focused playthrough including paper trail.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
