Very creative and unique gameplay: This is not only for the combat system, also the way to start the fighting by means of grids. This raises the tactical level of the game a lot, meaning that fighting is something more than attacking with one skill or another.
About the conplexity: I admit that I had to play about three times and read carefully the written guide here to understand a bit how the combat system works. Little by little I was taking the rhyth. Although I am sure that a player not very experienced in tactical RPG could feel frustrated fast.
In my opinion I do not think that the combat system is like the calculation of integrals, I have played games with more complex systems. the game needs a better explanation for to understand it, I think this case is better if the game is explaining step by step, how to fight, what is done here, what is done there, also suport some rookie strategies so that the player has something to start playing with.
For example: in Street Fighther, there is an incredible amount of complex techniques, but the first tutorial explains one or two movements (haduken and jump-kick). this tactic works well with levels AI and the player will feel good to win, then when you want to face more difficult AI you will realize that your tactics can improve much more when learning new techniques.
It is not bad to have a robust system with many options and strategies, it is something that your audience has, "but a great power with a great responsibility". If this is the system that the game really needs and you want to put it on, maybe instead of taking things away to make it simple, it's better to segment it and make the player learn it step by step.
The game has a good concept and has a promising gameplay, it shows that it is an idea worked with details, I hope that some of this will help you for a future version.