Thank you for your kind words and for sharing your impressions. I was thinking about what you suggest, and you are totally right. All "building" Cards (trees are buildings as well in my object model) are giving feedback when player hovers them - but the "event"/"tutorial" cards do not. That's something I will change - for all of them I can give proper feedback in the games world. Thanks to your feedback, I realised that something is missing here.
The zoom is also a valid point - I also had to remove the fog of war, because of performance issues. I will have a look at both topics later. When the fog is back, it should also be easier to orient yourself in the beginning - only a small portion of the map around the player will be visible then.