It is very difficult, perhaps to the point of being unfair in some missions.
This is exactly the way it should be, Battle Worlds delivers exactly what I wanted out of a Battle Isle inspired game. For the new lower price with the extra content? It is a great buy.
Just be aware that there is a steep learning curve with this game. And when I say steep, I mean you will fail the first mission over and over until you "get it".
A few tips:
* save often
* You can call for reinforcements, once every 10 turns. Use this until you get the hang of the game.
* Capturing buildings will often get you new units. You are probably doing better than you think.
* Move your units first, then attack. You get a bonus for having multiple attackers "flanking" an enemy.
* In the first mission, move North as quick as you can, taking the left path and ignoring the South East base. Once you take the North East base, the rest of the mission is easy.