Build simple website with Bootstrap

Hi, I want to use bootstrap for my new project.
It should be a very simple site with a user login/registration. The user can just edit a few settings and play a game.
My question is, should I use a CMS or PHP as backend?
A CMS seems a little bit heavy for me, because I don't need a gallery or text content management.
How would you set-up such a simple site?

See original post by Lucan