I took me way too long to figure out that the last castle needed to die. A health bar would have gone a long way, as I thought I was just waiting for all my units to leave the map. It's an interesting concept and is interesting once you learn all the mechanics, but I only figured everything out as soon as the game was over.
Yea the "Defeat the castle at the end" objective isn't really clear, I didn't have too much time to finish it up and I forgot to add an attack animation and health bar to the castle soo... yeah sorry about that :P
I'm also quite bad at making tutorials and sadly, this is the best one a made so far :'D
If this gets made into a full game, I'll make some tutorial mission, that should be good for an explaination.
Also, thank you for taking your time trying to understand the game, we really appreciate your effort :D