Amazing at a glance. Maybe even at second glance... but eventually you'll get bored.
When you first run through the campaign it seems incredible. Not just the beautiful graphical achievements at this point unseen in the real time strategy world... the attention to detail, varied unit type and different strategies you can use all give it an amazing first few games, at least. There are simply many things to love about this game, such as the addition of the cannon, and the effect it can have on the battlefield along with other unit choices and battle strategies - something I found the other AOE games didn't quite have, where usually brute force would do the trick.
I also mentioned I play this on occasion in LAN games with my friends, as it makes quite a fun gaming session for one or two games. But recently for me, this has where it has stopped.
After going through the campaign, and subsequently figured most of the game out, I began to see that the depth didn't go quite as far as I thought it did. Yes, there are strategies you can adopt to your style of play by using a certain type of card, building a certain type of unit, or using a certain battle tactic... but beyond 3 or 4 things to change such as the things I just said, most of the game stays the same, and you will EVENTUALLY get tired of the usual 'attack or defense' choice you make when building.
In short, it has depth, but there is simply not enough of it.
For me and my geeky friends, it's fun to have a blast from the past and rock out the games we were once completely addicted to such as this one. But at the end of the game for some reason we aren't quite as keen for a rematch, and in my opinion this is because although the game looks designed for playback because of the difference races and units, the playback simply is just not deep enough to make it worth the while. This does not mean I will not on occasion go back to Age of Empires 3 for a round or two, because for the most part this game hits all the right spots for the real time strategy player.