Straight up a good game; I played the final date several times after beating it just because it's that fun. All it needs is the ability to check my deck on the world map. Simple effects combined in fun ways, a split development tree, a final sequence that scales to your deck's strength... Elegant, simple, and fantastic.
I really love this game. The only thing I could possibly think to add would be some reward for clearing a date with extremely high values.