My first try on the player attack animation has been a failure : it was too long to trigger the actual attack after player's input, and broke the gameplay.
So I cut out most of the frames and had this :
It's really ugly, but fast : 3 frames. Useful to test gameplay and stuff. With this I was finally able to work on a (modest) fighting engine in Unity.
Later, I replaced it by a new animation, almost as fast to trigger actual attack (attack collider is enabled on third frame), and better looking.
I still have huge amount of work on this : it would be nice to have 2 or 3 attacks in a combo, a special (charged) attack... and a jump attack wouldn't hurt, too. All this work is sometimes overwhelming.
But let's enjoy today's victory : I'm happy to see it in action & cut heads with a decent animation.