The concept is genius. I mean it really gives chess vibe, even through my first thought was "Ah, so it's just TD game with chess graphics". It's something I enjoyed playing - which is a lot in game jam projects, because most are just prototypes with no real gameplay value.
That said:
-sometimes you cannot move a piece anywhere. Bug.
-sometimes you cannot move a piece because it's surrounded with other pieces or the path. But you can still save it from destruction by just selling it before the rocket hits. Seems kinda exploity to me.
-sometimes there is just no time to move all your piece to safe spots before the wave ends. It's frustrating, because you literally get punished for something you had no influence over.
-After moving piece it should leave piece submenu automaticaly. It's annoying to click "back" every time, and it consumes a lot of time which sometimes is not enough.
-It could be neat if I could see what piece could be moves, and what could not without checking every single one individualy.