Red Ronin

You can check the walkthrough section to see how to easily complete the game without dying and under 1 hour.

Here's the link:
https://www.trueachievements.com/walkthroughfull.aspx?walkth...

I just finished the game but didn't unlock this achievement, strangely enough I instead unlocked the achievement for beating the game in under 1 hour, I think they might be switched around or have the wrong description.
After beating the last boss and completing Chapter 8 you'll watch the final cutscene and the credits will start to roll, at that moment the achievement should pop.