Thank you so much for the feedback! I’m really glad you enjoyed the game. Your suggestion about giving the upgrade cards some sort of “class” is actually very interesting — I’ll probably add something like that in the future to help make the choices clearer.
As for the large empty area above the main map: that was originally meant to be another biome. It was planned to be one of the game’s mechanics, but it ended up being cut because of the limited development time for the jam.