Played the game again on legendary difficulty and it was a lot more fun than halo 2. The difficulty felt well balanced and less reliant on RNG and the sandbox is also well balanced as every weapon felt useful in some way I didn't have to just rely on a plasma pistol and a BR the whole time. Ammo was plentiful and the whole adventure was just really fun to go through again. My only issue was the transforming flood guys especially the long range one's they almost got me soft locked a few times.
And yeah the story kicks ass