If i didn't Miss 2 things I could have done it on my first play through in about 10 - 15 hours, I have tried it now on multiply accounts and if you know the right places for things it is easy to do in 5 - 10 hours no problems But I think it would also suit 10 -15 easier
And I'll work on my Sig for you Now
Edit: Is That Ok for my sig?
And Ninja the Arcade version would take up to a week with its Difficulty Curve