If you liked AOE: Age of Kings, you'll like or love AOE: Mythologies
I, however, am a huge Crusader-era fan, and naturally jumped on Age of Empires: Age of Kings - which didn't disappoint. The next logial leap was to try Age of Empires: mythologies, and I can say thankfully, that the game is just as good or better.
You'll be particularly pleased if you're a fan of ancient mythologies, as you'll traverse the single and unfortunately short campaigns with the ancient Egyptians, Greeks, and Norse. "Special" units are created which are the hallmark of the game, and will depend on the ancient mythological civilization you're playing. Examples include medusas, chimeras, and more. The use of "God Powers" further enhances the battle strategy, and is also a welcome addition.
Overall, a compelling game that is worth playing. The DS should have much more of this type of genre.