The introductory missions kick ass and I do love the evolution of the story and the worldbuilding. The cutscenes look fantastic even today.
But it didn't keep the strong momentum going and with it leading to a cliffhanger ending, I didn't really feel anything. However that is in some part to Halo 3 actually being the first game in the series that I played and I love that game, kinda hyped to replay it after so many years, so I lose the build up and suspense that must have been off the charts for people playing this when this had just come out, so I won't knock it for that. And it does end on a kickass line.