I was expecting it to be much more Mythology style of gameplay, which put me off as I really couldn't get on with Mythology at all.
Upon starting the demo I encountered a wow moment, the tune from the AoK playing, bringing back very fond memories! Awesome start. First order of business was going into graphic options and turning everything up, I fire it into a widescreen resolution, wow it really is widescreen! Awesome, take note BFME developers! Doesn't run very well @ 1920x1200 with everything set to high so I go for a modest 1280x768 with everything turned up, (after playing it I ordered a Radeon X850XT PE that should handle it).
Gameplay, wow it's much closer to AoK then Mythology was, I was very concerned about the size of battles just feeling weak after games like Rome Total War, BFME and the like, but this nails the skirmish-sized battles perfectly, when you que up military units like infantry they actually get produced in sets of 5 which is cool too, they're still individual units however (unlike RoN or BFME etc).
Graphics very impressive, obviously, we've all seen the screenshots, I however was surprised with the amount of stuff in the world, little things like ducks and swans on ponds just give it a very nice feel. Now what I've most been blown away by the sound! It's awesome you let fire a bunch of cannonballs into a building and wow, my sub was rumbling away, awesome stuff, it really makes cannons feel powerful, but it's not just cannons that sound awesome the whole world does.
I wasn't planning on picking this game up until it was a bit cheaper after release, I thought Black & White 2 and Oblivion were going to dominate the last quarter on the PC, but Age of Empires 3 is right up there with them where it should be.