i found reach to be fairly easy, is it worth doing this solo as IGN say its a hard campaign compared to other halo games?
Well, like Halo 3, it’s a difficulty roller coaster.
In some bits, you’ll be able to breeze through with a few well placed shots and strafing, and in others, you will get completely decimated.
It’s not really hard. Just some areas are time consuming since enemies each bullets like no other.
It’s not hard at all, I think I was stuck on a few lvl’s for a minor 15 minutes but after you just chill down and take a deep breath you’ll get past those
Yes, it’s very difficult. Especially when you get to the point where you have to fight BOTH the Covenant and the Promethean’s. I suggest take your time on each mission try not to rush things. That’s how I’m doing it so far and I’m at the 6th mission already in like 5 hours. One last thing, when you get to the forest part pick up the Promethean Knight’s auto-sentry. That thing will save your life and get you out of trouble a lot of the time because you’ll be running out of ammo constantly and will have to resort to camping and spamming auto-sentry. 
I did it today… It’s not as bad as reach but I need to take frequent brakes or I would have been to mad to play. After the long road one of my commendations didn’t unlock so I have to do it again
I had more trouble soloing this on Legendary than I did Halo 1. Most of the game you get screwed over and have to use the useless Light Rifle. The amount of shots needed to kill a Knight with it compared to the other precision weapons is ridiculous on Legendary. Not to mention the lack of precision weapon ammo.
Yeah it’s pretty bad. The third and eighth levels are probably the worst. Keep the auto sentry / hologram when you get them. Camo was nice but I never found it again past the second level. Everything else is useless.
Oh and I forgot to mention. Since 343 can’t make it challenging in a “skill” based way, they used Artificial Difficulty which basically turns it into luck based. Have fun getting 1 shot head shot by anything carrying a Beam / Binary Rifle. It’s even worse when it’s a Knight using the Binary Rifle since nearly any time you run into one using it you’re stuck with the Light Rifle.
Completed 6 levels so far. Harder than Reach but easier than other Halo games. Maybe that’s just because I’m more skilled now.
last part of level 8 was a -Yoink-…took me two hours or something