The game world was huge, as is usual again with Beth games. Tons of places to explore, tons of quests. You could almost get lost in it, except for...
Fast travel which, while convenient, completely ruins the hardcoe mode. I never once was at risk from dehydration, hunger, or sleep. Mostly an inconvenience instead of an additional element of danger/survival. Could have been handled much better - even just something like risk of random encounters when fast traveling, and/or having fast travel only usable on safe® roads and not from just anywhere.
Quests had too much of a 'hand holding' element to them. Quickly got so used to just following the arrow instead of paying attention to what NPCs said that occasionally I'd find myself in the middle of a quest with no idea what is even going on since I'd just been following the arrows. Would have been nice had there been a bit more sleuthing involved, although I can understand not wanting players to get completely stuck. Some quests were also pretty buggy or overly convoluted. There were definitely some fun quests however.
Dialogue was good for the most part, really enjoyed some of the more comic characters and the voice acting was good. Minor problems though, NPCs using different voices for common/recycled phrases than their regular voice and NPCs acting completely oblivious to situations they should obviously be reacting to, etc.
Combat was pretty meh, the novelty of the gory explosions wears off while there's not much to keep it interesting otherwise. The jerky and unnatural movement, the awkward/off iron sights, several guns(revolvers in particular it seemed) effectively jamming due to a bug(I think). The more challenging enemies simply kill you in 1-2 hits while your best bet for killing them is killing them in 1-2 hits. Not to say fast paced/deadly combat is bad, but in New Vegas there just wasn't anything all that fun/challenging about it. I also felt the game could've used a lot more options as far as weapons and armor, although part of that is probably because over half of the existing ones felt near useless - not because I wasn't @ high skill levels but because they were awkward to use, their ammo was too scarce, or they did pathetic damage. I went for a long time before upgrading from certain items. Weapon mods were nice, but not numerous enough in terms of availability and variety.
I didn't use VATS other than on rare occasions when feeling lazy. Not being able to use VATS to target body parts with melee, and it's very short range before your real time accuracy is better are a few of my issues with it, but mostly I just didn't like the system. Didn't really feel like an interesting hybrid of turn based and real time, but more like VATS was just there to make dealing with fast moving things in close range easier.
Skills were handled fairly well, as usual some arguable duds but the various dialogue checks and ways to avoid conflict with non-combat skills was nice.
SPECIAL was sort of the same deal, with perk requirements being the main reason to take certain ones. Charisma was pretty worthless though, I went through the game with 6 but felt like it would've made almost no difference had I only had 1 and min-maxed more. Perception other than being required for better criticals was also pretty lacking IMO.
Perks were a mixed bag, I felt reducing the total number of perks ended up being a bad limitation - I ended up simply skipping the more fun/flavor perks for more combat effectiveness. Certain perks were overpowered while others were simply useless - particularly the experience increasing ones dude to level scaling and level cap.
UI was pretty bad, luckily this was something modders were on top of quickly, but the default was just so awful for PC with very few customization options I felt it worth noting.
Reputation was definitely an improvement over karma, however they should have just removed karma completely - it really got annoying. A lot of the karma gains/losses were pretty much nonsense. For example killing a certain "evil" faction gives you good karma pretty early on, but you'll notice taking the items near them after they're dead gives you negative karma.
