Do I have to complete the game in a Let's Play

[Guu]

Depends how you want to present yourself. There's no rules to let's plays and how they are handled, only you make the rules here.

But as a frequent viewer of said genre, I'd suggest either not show that stuff or just stuff it all in one large video and set it aside. I mean, I guess it really depends what kind of let's player you want to be; the type that makes glorified walkthroughs or just a straight up entertainer.