Here are two random examples, nothing perfect but pretty much says it all for me.
The overhead lights (how are they even on? - there's no generators or power in the building from what I can see, though let's assume for argument's sake that they are turned on), are way too bright for not only their physical type, yet their texture indicates they are dim, damaged and possibly not working.
Yet beneath, the area is lit up like Christmas at the Oswalds.
What makes it worse is all this smoke floating around in indoor locations. I thought I was on a airliner to Washington in 1966 - couldn't see five feet in front of me with all the mile high cigar smoke.
High saturation+ high contrast+constant smoke = one head ache of an experience.
The shit's so bright I can see flees jumping off Dogmeat's back.
And AND! You can't shoot/turn off any lights, except the spot lamps/defense lights.
Also, what is every one doing in terms of loot management and carrying capacity after you wipe out an area of enemies? I noticed that if you fast travel and return all the bodies are gone. I've been rounding up all the loot after a battle, stuffing it in some container then making trips back and forth to scrap or donate it back at Sanctuary.
So, a moment to frame this. My recent experience with Fallout 3 and New Vegas means that my opinion is based off of games which absolutely required you to set gamma through the roof to see anything with the pip-boy light on.
Framing the discussion with that the lighting engine here at least allows you to see things...most of the time. I've been in the middle of building a base, and the lighting engine seems to just decide that a light won't generate any light. It's frustrating, but par for the course Bethesda. The particle effects are a drag on performance and lighting. I've found that by setting them, and god rays, low I can have a playable experience in the "downtown" section of Boston. It's kinda depressing, and they definitely need to fix that.
As far as loot, I was a pack rat. I explored the overworld, until I found a settlement. Once a settlement was established, I cleared out an area. I waddled my over encumbered butt back to the settlement, where I could strip everything down into components and build up a settlement. It's frustrating that the fast travel while over encumbered perk is locked behind such a high level (and 3 other perks), but it's definitely worth the investment. Problem is, by the time you've gotten that high of a level you're likely to have unlocked enough settlements that lugging around all that crap is a joke. I mean really, you get one 0.2 lb piece of steel from a 2.3 lb piece of armor? WTF Bethesda, I can get the same item from a 1 lb tray. The response they gave us was "people testing the game don't sell things, because they turn it into crafting items." The PR should have read "People don't sell things because it takes a 1500 cap investment and a ton of resources just to make a shop to sell at, and the shop has a budget of 250 caps so you can't really sell anything."
The game has problems. My top ten list of required fixes are as follows:
1) Lighting and particle effects - optimization so that they work without slowing the game to a crawl.
2) Balancing (weapons). Obsidian got this right with New Vegas. The top tier of each weapon style had a contender. Ballistics had the anti-material rifle, plasma had the rifle, and laser had its rifle. 4 works under a simple equation ballistic<laser<plasma. All the investment into ballistics might as well be useless when the .50 modification for the sniper rifle doesn't one hit enemies. Laser offers more damage, lest time between shots, more capacity, lower carry weight, and only winds up costing resources and having a minor accuracy (110 versus 112) penalty.
3) Crafting. Breaking down a bunch of crap to decrease settlement size, just so you know what you actually have, is a joke. I've had 2000+ lbs of crap to break down after going on a mass harvest of my settlements, which allowed me to reset the build size. If I could dump everything into a built device, and press a button to convert everything into its components, I'd be able to save hours of mindless clicking. On top of that, why does a 160 lb weight get converted into less than 20 lbs of lead and no steel? The breakdown of items is just idiotic.
4) Ammo. I'll say this again, Obsidian got this right. Common ammo produced a small number of resources when broken down, which can go to making useful ammo. Sorry, but 1000+ rounds of .38 ammunition disappeared insanely fast when I went hunting mirelurks. I want to break that .38 ammo down into .45 ammo, and absolutely murder a mirelurk with two shots to the face.
5) Settlement defenses. What absolute BS powers them is beyond my understanding. I don't always get notifications that settlements are under attack, when I do sometimes it's in the middle of a mission (and I can't get there in time), and even when I do sometimes they just bug out. The only hard and fast rule is that you fast travel there, and by the time you fully load your turrets have chewed through 90% of the attackers without any damage. Despite this, if I don't fast travel back the base is severely damaged. Why am I defending these places, if the defenses aren't repelling invasions? Heck, I've seen a party of supermutants lasered into ash outside their attack range and the assault sentry (near the murky settlement) lasered and missiled to death before opening fire. That kind of firepower should make defenses automatic, yet somehow it doesn't.
6) Settlements. Heck of a lot to cover here. Let's cover the basics. People shouldn't be captured if defenses would prevent raiders from ever entering the area. The occasional synth discovered, then murdered, inside settlements is good for flavor but means I have to keep those recruitment beacons on. Supply lines are crap when you get a maximum of twenty people, and all resources are shared only point to point. If my supply lines cover four settlements the resources should be shared everywhere. This point to point crap means 30-70% of my supplies can't be seen no matter where I am. Let's also add to this so truly crap settlement locations (Croup Manor and Hangman's Alley), where my people can be murdered while on a supply run if I'm anywhere near them (and thus enemies can spawn and murder them).
7) Perks. If you're going to institute a building system which requires harvesting everything and yields much lower amounts of resources than weight implies, you need strength and perks related to that. You also require charisma, to setup supply lines and build crafting stations. Intelligence is required for levelling, this means that to play with the new mechanics you need to have a character with low perception, endurance, agility, and luck. That means that you either forego content, power level, or compromise your build to get things setup. None of these options is acceptable. On top of that, there are some pretty broken perks. Combine the sniper and rifleman perks and you'll be unstoppable outside. Want to murder an alpha deathclaw, just open up with a combat rifle and the stagger will prevent retaliation. Want to actually make power armor an option, you'll need an enormous intelligence to get the nuclear physics perk to double fusion core life. Offloading the leveling system as they've done just makes you feel like they're incorporating the worst part of JRPG level grinders into a mediocre western RPG.
8) Enemies. The AI is just terrible. I've had ghouls be functionally invincible because their lunge makes them impossible to shoot. Likewise, I've watched settlers face off against a supermutant with only their fists while others chased enemies cross country rather than accepting their defeat. The old enemy bullet sponges sucked, but at least they had reliable actions. Now the AI seems to be fighting over whether it wants to murder you, or kill itself to avoid the embarassment of being dropped by a pipe pistol.
9) Base components. I look forward to finally getting solid items. The wood and metal items having holes makes no sense. You've got aesthetics winning out over functionality, while the item pallet is decidedly small. This needs to be rectified with a massive content patch soon. If not by Bethesda, the community will gladly do so.
10) Companions. This is...tough. The companions are chatty, and after the fifth time they question why you pick up that microscope because it's junk, murdering them seems like a good option. Between that, and Strong particularly hating almost everything (lock picking, getting into power armor, etc...), getting the minor bonuses they eventually offer is at best a dubious proposition. Then you've got things like Preston's perk, which is functionally invaluable because you never get attacked by less than three enemies unless they're a boss. I wish that the companions functioned like the SINK from New Vegas. You could shut them up once they became annoying, yet their inclusion inside the game was funny and awesome for a time.
In summary, this is a Bethesda game through and through. There's plenty to enjoy on the surface, all built atop a pile a failure. If you want a couple of hours it's a great game, but by the time you can realize all the mechanics (as they are hidden behind level walls) the inherent flaws are visible. That which keeps you going is a love of the story and world, because it definitely isn't the mechanics. The community will, as usual, have to go back in and fix them for this to truly be a great game. It is much better than 3/New Vegas in terms of stability though. Bug riddled, but stable.
