The level is often a problem. I started gaining levels in the very first mission. You should start with two heroes (the second one for gathering and scouting). In the upper right corner, there's a ship with ghosts; it has many crystals, and to the right and down, there's a mine.
Added 7 minutes later
I easily completed it.
Added 21 minutes later
Version 1.8.
And another tip: replay the first mission and execute Martina; it will be easy to gain points in this mission. The fort in this mission will be guarded by a weak squad (a few guards and, I think, that's all, without any Guardians or Griffons, etc.).
Added 5 hours 51 minutes later
Besides, there are still 2 weeks left. It takes 3-4 days to reach the fort.
Later, they seemed to disappear somewhere. In any case, I defeated them on "easy" difficulty using the auto-battle.
I actually let Martina go at that time, considering the "Tears" aspect.
The second hero is with the Architect and gathers resources. He also went north, where you have to travel by water. For this, I had to give the previously joined guards to the second hero.
