Some goblins seemed to heal sometimes or something. maybe visualize that better or is it a bug? Not sure about what you should do after the area is filled with your troops or trees.
you could go many directions from here: expand tile area bigger, cut trees for resources to expand or build something?, stack troops for more powerful ones. add variety of ways for them to interact, like using swords and shields and healing etc. etc...
anyway nice looking game, but it is missing gameloop like you said.