Wow, awesome job, Cody.
I am really happy you were able to play the game on your PC without a video card. The fact that the game runs pretty well on your PC at 800x600 is a testament to the scalability of the game. What remains to be seen is how the framerates hold up when there is a lot of action on-screen. I remember AoM freezing up a couple of times for a few seconds on a slightly underpowered machine when there was too much activity on the map.
Since Cody has covered the Skirmish mode in quite a detailed manner, I will focus my attention to the other parts of the game. First off, the Campaign mode. The Campaign mode seems to be divided into three Acts, each Act dealing with a different part of American history during the time of the colonization and industrialization of the Americas. The Acts are called Blood, Ice and Steel respectively, and for the demo, only two missions from Act III - Steel are available. Just like AoM, the missions are unlocked as and when you clear them, allowing you to proceed through the story the same way as in the previous AoE and AoM games. The history behind the story is well researched, and even though my early American history is vague at best, I am sure the game draws from events in history pretty accurately. The events and characters in the AoE3 demo at least, aren't as well known as William Wallace or Joan of Arc from AoE2. (From a small precursory search on Google for Major Cooper, it seems that this was a circa 1850s Major after whom Fort Cooper in Florida is named, and played a major part in the Second Seminole War.) The game, in classic AoE fashion, also allows you to replay the missions you have already cleared. The Difficulty Levels are as usual - Easy, Moderate and Hard, seeming to break with the multiple difficulty options presented in AoE2.
The game draws heavily from its newer predecessors, namely AoM and RoN, not to mention, some cues from the "other" famous RTS - Warcraft III. The cutscenes in the game somehow eerily resemble the ones from Warcraft III, although with a lot more detail. The cutscenes are rendered in-game but are sometimes rendered in the normal plane instead of the usual isometric view, which adds to the realism of the game. Each character that's currently speaking has a light circular halo under it, like the way W3 used to highlight characters that are currently speaking. The cutscenes in the demo appear to switch freely between the normal plane and isometric view, but the game doesn't seem to allow the player to switch to the normal plane view ever.
The presence of the Havok physics engine is easily noticed. Explosions send chunks of rock and debris hurtling from the damaged structures and the smoke and firing effects are absolutely world class. The game's minimap allows you to find heroes, use signal flares, talk to other players, and use the Advanced and Toggle functions of the minimap, which doesn't seem to have changed much at all from it's predecessors. Resource gathering is again through food, lumber and gold. Markets and Trading Posts generate gold and experience, and the Experience Points accumulation paves the way for what the key feature of AoE3 is - Persistent Home Cities.
Persistent Home Cities is EXACTLY what the name indicates. The Home Cities that you build for yourself and the technology upgrades and improvements that you make persist over single player as well as multiplayer games. The other previous AoE/AoM/RoN games had the problem where all changes you made to your Home City or Base and all the technology that you researched and unlocked were lost once you finished the mission and moved on to the next level. Even though the next level would be set in the same place as the previous one for some missions, the system would arbitrarily select the Age and technology that you had available and you had to do everything all over again. This is not the case with AoE3. Persistent Home Cities ensures that you will never ever have this problem with this game.
Of course, this brings up the obvious problem. You might like different strategies and different researches, more of a certain building type, etc. for different maps and different playtypes. For example, I don't want to create a settlement with lesser protective walls for one map and then have it demolished in another scenario where it would have better to have more walls and more outposts. It also works the same way with resource collection. Sometimes I want more resource processing structures and sometimes I want more structures associated with the war machine. To solve this problem, the game allows you to maintain and create different "decks" with multiple "cards" in them, allowing for different maps and strategies. Also, like RoN, each Home City is unique for a culture and there appear to be certain "bonuses" associated with each culture and each Home City and the technology available for it on the Research and Upgrade trees.
Also, as Cody pointed out, the Home Cities can be a place where your experience points can get you more food, gold, lumber, settlers, combat units, trade caravans and advanced weaponry, depending on the Age you are in and the number of experience points available. This feature appears to be a bit too easy for advanced RTSers, since Experience Points keep accumulating steadily as long as you play even averagely and can then be traded for more goodies without even breaking a sweat. In addition, the Town Centers can be upgraded to more advanced versions, and here, more of AoM inspired tricks come in. Just as in AoM, where upgrading required to select and ally with one of the Gods/Goddesses, upgrading the Town Center in AoE3 requires you to select a Politician from that age to ally with. Each politician requires a certain amount of conditions, resource or existing military establishments and provide different benefits. For example, allying with an Admiral would give you Dock benefits, while allying with a Marksman would give you extra military units. So far, from the demo, its not known whether allying with some units would grant "special" upgrades, such as a special unit or a new building or upgrade.
Talking about all of this, its very important to focus on micromanagement. Since quite a number of people found the micromanagement and upgrade/research paths in RoN to be a bit tedious, Microsoft and Ensemble have stuck to the traditional Research/Upgrade trees with this game, to continue to keep existing AoE players who might be put off by too much of a change. Cody already pointed out the part about resource gathering and micromanagement, and it seems to work fine, freeing you to colonizing the world, rather than worry about running out of food or wood. Drawing once again from AoM, each single player campaign appears to have two Hero characters (highlighted by a white star beneath them), and while so far, both Hero characters are always available, it is unclear whether there will be missions that will require the Hero characters to work independently of each other or not. Also, if a Hero character is gravely injured, he/she doesn't die and then be revived as in AoM, but simply lies on the ground, writhing in pain for quite some time, healing slowly and then limping away. Its also unclear whether this will be constant throughout the game or whether there will be a set number of times that the Hero character can be gravely injured without dying permanently and ending the mission as a failure.
Building and repairing is done through Settlers, who can build Manor Houses, Town Centers, Mills, Farms, Docks, Outposts, Barracks, Protective Walls, Churches, Firearms Ranges, Stables, Blacksmiths, Arsenals, Mining Posts, Trading Posts and a lot of other advanced structures, depending on the Age you are in. Settlers automatically find work, and do not seem to be lounging around uselessly, making you search for a "Find Idle Villager" button everytime you want to make sure everything's ship-shape.
The sound system, as always, is top notch, and the music, classic AoE. The sounds of the various units and the battle noises are recreated superbly and voice acting for the Heros are extremely professional, and the whole of the game is acoustically A-class. The graphics aren't genre redefining or groundbreaking in any way, retaining the look and feel of the classic AoE, but the small things that you don't really pay THAT much attention to make the game visually very appealing. For example, the smoke effects of a passing train, the tiny muzzle flashes from the weapons, the debris from a building being attacked, the shadows on the ground from buildings and trees (which are pretty darn realistic and depend on the position of the Sun, the building and your perspective, as in real life) and all are rendered excellently well and lend a bit more reality to the game. The game also allows you to zoom in to a Warcraft-III level zoom detail, but its no Rome: Total War. Don't be surprised if the game looks more like classic AoE rather than reality.
The single player campaign for the full version of the game will feature 8 European civilizations, 24 Single Player Campaign scenarios, 15 Random Map games with multiple civilization options and Skirmishes with 7 computer personalities. I haven't had the opportunity to try out the multiplayer aspect of the demo yet, but a simple glance already showed quite a lot of people playing online. The game also features online matchmaking via the Ensemble Studios Online v2, pairing you up with someone who's the best bet for you as well as allowing you to play with/against your friends online. Load times for the game are superfast, even faster than AoM, which is something that surprised me.
All in all, AoE3 looks to be a surefire success once again in the RTS world. I can't wait for the game to release. I hope Microsoft launches the AoE3 Collector's Edition in India. I really do! In the meantime, here's some screenshots to whet your appetite. More information on units and strengths, weaknesses and tactics and a rudimentary strategy guide will follow soon.
AoE3 Load Screen
Main Menu
Campaign Mode - Selection Screen
Cutscene
Home City and Trading
Objectives Screen
Hero Units and Market Options
Units, In-game Menu and Unit Upgrade Options (Stable)
Town Center Upgrade - Affiliation/Politician Selection
Town Center
Settlers - Various Build Options
Skirmish Mode - City Creation Screen
Closing Screen - Full game features
The final verdict on the demo:
GAMEPLAY: 9/10
GRAPHICS: 7.5/10
SOUND: 9/10
FUN: 9/10
VFM: (based on download size for the demo): 9.5/10
TILT: 9/10
OVERALL (not an average): 9/10
END NOTE:
Reviewer's System Configuration:
Intel Pentium 4 Extreme Edition 3.2 GHz
Corsair XMS 2x512 DDR400 Dual Channel
Gainward GeForce FX 5950U Golden Sample
Western Digital Raptor 10kRPM SATA 80GBx2
Creative SoundBlaster Live! 5.1
White , 8) 8) Black..even 
