Yes, you got the point about the rocks. Im thinking about changing that because it is somehow hard to manage for the player.
EDIT: I played on my mobile where you don't have the clue "hovering" a tile. The blue mark on PC make things easier.
The issue for me was that it is hard to guess where you'll end up. Maybe too hard to implement for a game jam but a visual representation of your Z and where you'll really end up would make the management easier (but maybe too easy some time)