I think this is a very interesting idea but, as it is now, it is very confusing and leads you to just copy the other player a lot because you are not able to plan ahead. I think that it could be cool to make the board asynchronous, so having the pieces in random spots from each other on each side like the game 'Really Bad Chess'. Another thing that could be helpful is to have half of your pieces be your "native" units where you know how they move. This would also give the feeling of humans that got some alien weapons but don't know what they do yet. You may also want to consider less movement that is jumpy, like the knight, and more slidey like the other pieces in Chess.