Played this to death as a kid and it is exactly how I remember it.
AoE2 is the quintessential medieval base builder that has you conquering your opponents through four "Ages", with progressively stronger and better units. Best part was they released an expansion after more than a decade because this game has such a cult following.
The game has you gather resources, build structures, amass units and go trapsing over maps of all kinds. These range from tiny islands to pretty decent sized representations of European climates that have you seek out and destroy your enemies or win by several other not-so-total conquest game types. The new expansion allows those maps to be massive and adds even more civilizations to play with, making the total 23. These civilizations span from all corners of Europe, Asia and the Middle East. All units have voice clips in their native languages to help with the feel of every faction being truly different in addition to visually unique buildings and units depending on the cultural locale of your civilization.
With its migration to Steam AoE now has great multiplayer support, achievements, and Steam Workshop capabilities that will allow the sharing of user-created content to be spread much easier than having to download things like scenario maps from a third-party webpage over dial-up as I did back in the day.
If you played this game in the past, it is well worth picking up again if nothing more than for nostalgia goggle syndrome because you know just how fun this was. If you somehow missed the boat in the past and are a fan of games like this there is literally no reason you should not own this game. It has been improved and will more than likely be considered one of the fine wines of gaming; Better with age and enjoyed even more with friends.