Yeah, so stupid about this collision, hidden by the cliffs, lesson learnt !
About the checker pattern, if I can give some insight. Playing at first I felt lost without any sign, I didn't have the animates waves either, so it became tough to understand. I tried with a grid at first, but it was ugly, too busy on screen. Checkerboard then felt like a much cleaner way of translating the grid to the player
Thanks for constructive comment !