new board game idea

so i thought of a new board game idea in the style of a classic board game how it works is that there is 1 board and 2 castles and the middle is the battlefield so in each players castle there is multiple pieces (you can also suggest piece ideas in the comments) so the first piece is the archer it can shoot arrow pieces above the enemies castle but doesnt shoot far the gunner can shoot really far but cant shoot over walls the horse rider can jump 4 squares or less and can jump over or on pieces and theres also the guards which can block bullets and arrows and can also attack pieces then there then there is the piece that can become any piece by going into the training area and theres also cards that select what piece it can become and also the training area can make pieces be able to 2 or 3 squares but it does take multiple moves so doing it alot can be risky since it gives your enemy time to set more things up and you can also lower the castle walls and you can also use bombs to destroy the enemies castle walls but after lowering the castle walls you cant raise them again

What's the game's objective?

the objective is to kill the king and the queen