I was absolutely enthralled with the game at first, everything really is so finely tuned in the beginning - difficulty so nicely balanced and a good challenge, but party strength and power in this game snowballs so fast and it just becomes way too easy
at around lvl 15 I just can't being myself to continue and finish a playthrough, its more of a chore now.
There is definitely a "boredom wall" right around that point in the game; you're not alone. The latter half of Luculla has this effect where the challenge of battles has been consistently decreasing and you begin to dread combat as an unwelcome chore. (The one place with somewhat difficult battles is the northern sandstorm area, which is manages to be annoying for the same reason it is difficult: reduced speed, impeding the exploration/travel element of the gameplay.) By the time I found Hunter's Edge I had almost totally lost the urge to fight things.
I can only imagine how many player D:OS loses right around that point, diverted to other more interesting things, leaving the game unfinished.
The beauty of the world is one thing which kept me going... sort of. I found myself actively avoiding combats just because they weren't fun anymore, enjoying the challenge of a stealth game more... although it was the moments when the stealth tension was gone and I could just take in the sights which I was playing for. I explored pretty much the entirety of the Phantom Forest zone as soon as I got the ability to safely pass the bridge, and then only after performing this task did I go on to fight battles -- the minimum required to get to the temple door, as determined by prior reconnaissance. The point is that exploring the world and picking up tidbits of hidden lore (contemporary Rivellon and/or Sourcerer era lore, not the Guardian stuff) could still engage me, much more than the battles could at that point.
This game truly is a wonderful one for just getting out of town and wandering about, taking in all of the wild-yet-tranquil environments the game offers you.
The core design of the latter parts of the game is still very sound, and I imagine that redoing portions of the story at this point isn't very feasible. It's just the combat which is off. I'm not sure exactly how to fix it, because the monsters steamrolling us is exactly as bad as us steamrolling them, and in a turn-based game there's a tendency towards temporary one-sidedness which may get out of hand if the enemies are buffed too much. But the core issue is combat not being engaging.
