No, Halo 5: Guardians isn't like anything Bungie ever made. No, it doesn't look entirely the same. No, it doesn't play the same. Do what you need to do to accept that the franchise is now in 343 Industries' hands and things will change as a result. If you need to think of it as a spinoff instead of a sequel, go ahead. Anything to give Halo 5 a chance.