Got about halfway through the game in 7 hours. Did pretty much every optional area/fight up to this point as well. Finished Hollows, defeated Sif, even some of Demon Ruins. Hardest fights so far were Sif and Capra Demon. The latter just because it's so in-your-face and can basically one-shot you in this situation. Stray Demon was also kind of a problem for the first time ever. Sif was easily the toughest fight overall. I usually do glass cannon builds if I can get away with it so this isn't much different.
Have +5 Divine Reinforced Club (mainly to be prepared for Catacombs). I've read that I should get a Chaos version done as well for bosses, might do that if I have the mats. +15 Pyro Flame, lacked the souls to get it Ascended +5 but I'll do that after I get the Lordvessel and can warp back there. When you aren't leveling at all you have a ton of souls for reinforcing the pyro glove (and it takes a ton). +5 Grass Crest Shield. Using Havel Ring for fast rolling, might switch it for the +20% attributes ring and just drop some armor.
Most of this game consists of dirty, grimy ruins. When it gives you something pretty, it's REALLY pretty. Which makes me think this is totally intentional, if the whole game were pretty, these moments of beauty wouldn't stand out nearly as much. Also they always follow a particularly deadly area or fight, like a reward.
When it comes down to it the Souls trilogy is probably the best "post-apocalyptic" game series ever made. One of the ultra-rare things that presents the idea of an apocalypse happening during a medieval era instead of a modern era. So you constantly encounter the ruins of the old world and the increasingly-sparse inhabitants trying to make their way in it. Demon Souls might be pre-apocalypse or mid-apocalypse if it's the same world, I don't actually know. It certainly has way more people in it. By the end of Souls 3 the final battle is basically between the last two warriors on the planet, finishing a war that ended long ago for everyone else. That's the impression I get anyway.