In this game, you are in charge of a nation (faction or whatever), and will try to take over the world. The other players will surrender when you conquer more than half of the castles. You can refuse this surrender, but after that the opponents unite and will try to wipe you out.
Each town produces certain units and a certain amount of money. The upkeep of units costs something, and you should save money to afford to buy a hero. Heroes can explore ruins and temples to get special items, gold or allies. That's about the concept.
Compared with the first part, this game offers several improvements, but also several steps back. In the area of improvements, I'd mention two. First, the game offers several maps. This supposedly adds to the replayability value. Second, the game offers a limited map editor. It works like the terrain editor in SimCity 2000 - you determine how many castles you want and what share of the map will be covered by oceans, hills and forests. The editor is surprisingly intelligent and creates relativelly compact maps, not in the style of Civilization random maps. If you like the map, you can save it and play later.
However, this game made a big leap back, which made it less fun than the original game. It is much easier, mainly of two things. First, you can buy different production in the cities. So if you don't like pikemen being produced in a certain city, you can dump them and buy, let's say, unicorn production. THis subtracts greatly from one of the main strategic elements of the original game. Second, you don't need to create navies anymore. Navies were always very costly and took forever to build in the first part, which was suitable for longer campaigns. Here, however, all you need is to send an army onto the ocean from a friendly city or a port, and it will transform into a navy itself. Thus, sometimes it is easier to conquer cities across the ocean than on your own continent.
I am aware that most of you will like this part better than the first one. However, if you are hooked up on the first part, ignore Warlords II.