That's a huge letdown, because the encounters feel tuned for co-op rather than solo play. Playing alone, I could feel the absence of other players; although enemies are tougher when playing with friends, having another person to divert a boss' attention feels more natural than having you and a boss circle a pillar as you whittle down its health, or slowly working your way through the unrelenting hail of bullets that some of the later encounters subject you to. You also get to revive your friends in multiplayer (you even get one self-revive), which makes some of the tougher fights a little easier.
Immortals Fenyx Rising's second DLC takes the game to an entirely new world, but it still doesn't stray too far from its old one.
Then, about three-fourths into my playthrough, I found a legendary warhammer with an unbelievably powerful perk. Whenever I used a Weapon Technique, it created an enormous bubble that slowed any enemy within it to a crawl. It didn't rely on a trigger, ailment, debuff, a percentage, or anything. When it dropped, I read the description in bewilderment. Was this thing for real? It was so out of line with anything else the rest of the game had given me that I doubted it'd be useful. But it was. It made tough encounters a breeze. It destroyed bosses. The rest of the game went by in a flash. It was the most fun I'd had with Godfall, and I held on to that warhammer even after it was one of the weakest pieces of loot I had, just because of that one perk. I wish I'd found more items like it, because it was a welcome change of pace.