Good graphics, interesting idea, but random level design doesn't do it any favors. Way too many situations where I'd restart a level after realizing I'd wound up stuck on a block that had no chance of connecting to anything else an time soon, and the frequency of the shifts mean that even when a path presents itself you can rarely act quickly enough to take advantage of it. Allowing certain tiles to have just no boards at all doesn't help alleviate any of this, and tens o encourage players to try and stay on boards with the most potential exits possible regardless of if that's going to take them closer or further from their goal. I'd also frequently wind up off in the middle of nothing as two boards disconnected during a shift.
Maybe try adding a little visual warning of some sort (water currents or something?) to let players know where boards are about to shift, and give them a quick warning it's going to happen. As is, it's a giant test of patience, and while not being in control of the environment is fine, as is there's not a lot of strategy or reason to the gameplay. You just move towards your next goal and hope for the best, then wind up waiting a lot, and it isn't very fun or rewarding, as even in victory you never really feel like you did anything to contribute to that.