Thank you for your interest and precious feedback!
I like what I did with the multiple difficulties setting. You are supposed to play in normal mode first.
A solution would be to lock harder difficulties and unlock them by finishing the game multiple time
but I probably won't do that. I will change the difficulties names instead:
Very Hard to Challenge
Challenge to Challenge+
Here are comment for each difficulty.
Walk: your characters are litterally invincible and you have infinite turns. for those who want enjoy the story
or newcommers to fire emblem.
Easy: a little too easy for my taste but a good middle between Walk and Normal.
Normal: this is the difficulty you should start with. Quite fun and balanced.
Normal+: same as normal but with permadeath.
Hard/Hard+: harder but still fair in my opinion.
Challenge/Challenge+: may seem unfair and unbalanced, as you have to abuse RNG to complete these mode and know the game very well.
Can you retry in Normal or Easy and give me more feedback, that would be very helpful.