First off, great job developing this game. The new game is great; the old game is too.
I think both should be included in the new version, especially since you had the foresight to allow different types of games to be played with the executable. The new game could be titled, "Freestyle" or "Fortress Freestyle," while the old game could be titled "Old School" or something of that nature.
Anyway, the Freestyle game and the more structured Old School games require different strategies, and have different game play. In the old game, you would immediately create a farm, to survive your first winter. In the new version, you no guaranteed with a river, so you seem to get more food and booz to offset that.
Also, a suggestion about the new game is that besides generating above world rivers and lakes that you generate underground river and lakes for the map, and underground magma river and lakes. Perhaps, viewing the three types of lakes on the map can be turned on and off with keys when the player selects his fortress location. That way, people can select a sites that has where the three level of rivers intersect, instead of trying to build sites near volcanoes that have a nearby brook.
BTW, do underground rivers still flood? I haven't found an underground river yet in the new version. But that was a major part of the fun in the old game. I liked the advanced Nile river farming system, where I fortified the walls around the river to flood my farm rooms