As far as I know 3 times with a few extra play throughs of the first game. I've probably gone through the original series about 10 times. And I've only been through Link once, don't understand a word and I am not a fan of the gameplay.
I played through G.U. 2 times and since then I havent had all off the volumes at my house at the same time.... the person who I loaned vol.3 to moved to the east side and its actually become a pretty rare title around here so i have to travel across the city one day into gangland and get it...*sigh*
Plaed through Gu vol 1 3 times 2 twice nd never finsihed 3. I gave up on Gu honestly. I think they are actually pretty bad games compared to IMOQ IMHO. And i am currently playing through my 5th file of Infection.