I did have trouble finding the last tablet, I think the digging could also use a sound effect. I also didn't know the flashlight revealed hidden pathways. I liked the shrinking iris air meter mechanic.
Viewing post in High Tide jam comments
Flashlight for hidden passageways was kind of a last minute addition, so it’s not explained that well. There’s a hidden passage near where you find it, so I hoped the player would find out either there or in the grid maze.
If you haven’t found the last tablet, I assume it’s the one at the bottom left of the map . There’s a hidden diggable area in the caves above, with the same shape as the hidden dig room on the right. . I was probably a little too cryptic there, ha!