Great game - released way too early
Gameplay:
Same old CIV goodness, the inclusion of unit XP is something die-hards have been asking for and it's well implemented and fits in the game well. The new Permanent Alliance feature is very interesting and adds some depth to the diplomatic front. The game feels true to the series, progresses faster in some ways and has that "just one more turn" addictiveness to it. Unfortunately, I was hoping there would be a little more added to the diplomatic front, I dunno what exactly, but a little more. It still feels very robotic and contrived to me, although making CPU opponents seem more real and human is very difficult.
Game Engine:
The game definately looks better than previous CIVs, but graphics really aren't all that important to the game. Unfortunately, in jumping into the 3D era, CIV IV has made more enemies than friends. There are thousands of people that have unplayable problems with CIV IV. Spend time on different forums and you'll see the littany of problems people are having, particularly people with ATI graphics cards and some Soundblasters. I am running an FX-57, 7800GTX, 2GB RAM, and 2 SATA 7200 RPM HDs, and MY COMPUTER has framerate problems in the late game. And I can NEVER zoom about above cloud level, so I'm forced to stay close to the terrain. Furthermore, loading save games takes WAY WAY WAY too long and the game suffers from long times between late-game turns. It's simply inexcusable. It's not my hardware, it's the programming. I've also experienced way too many drop to desktop and complete power down crashes, something I can put up with to a point, but gets old.
Interface:
This is where I find the most problems with CIV IV. I really think the interface could use substantial improvements, many of which might have been done if the game had spent more time in development. The city screen is awful in my mind. The center area where you can assign CIVs to tiles is way oversized for what it's needed for. The production queue section [probably the most used] is totally undersized and relegated to the bottom of the city screen. Deciding to use icons for units and buildings was a mistake in that space, it's really annoying to scroll through what you can build late in the game. Also, while you can save production queues, I would have liked the option to view/edit those queues without having to load them into a city.
I am a customization freak, I'll admit it. I run BBLean as opposed to the default windows shell and really like to tweak things to my liking. Maybe it's unfair of me to criticize CIV IV for lack of interface customization, but I am going to anyway. Anyone familiar with Morrowind can testify to how refreshing it is when you can drag/drop/move menus around to wherever you want on the screen and customize your player screen. I think CIV IV could benefit tremendously from such options, let the user move stuff around, resize things and put them where he/she wants them. Elite CIV players spend a lot of time optimizing individual cities and I'm sure we'd all appreciate such additions.
Conclusions:
CIV IV is a great game, but fails to make advances on some fronts that I had hoped. Furthermore, the game was released too early, it needed more development. Hopefully a patch will see many of the game-ending problems corrected for the people who can't get the game working properly. So, at this time, I am scoring the game kinda low because of those problems, it isn't fair to game buyers to have them buy a game and have to wait a few months before they can play it properly. Considering that longtime CIV fans would have bought the game whenever it came out, I think Firaxis hurt themselves with the early release, because newcomers might experience a bunch of technical hang ups, and not get into the game like they would have otherwise.
Ultimately, I expect that after some patching/fixing the game will be every bit as lasting as others in the series. My scores are all lowered because of what I consider an irresponsibly early release of the game.