So if you talk to Alma at the end of the tutorial she will say "looks like you pretty much found em all" or something if you have indeed found them all. The empty slot in index is something I'll adjust in a future update. I just have been adding rows of 5 at a time so it incidentally landed with one empty slot this time around.
Can climp up the rock near pyramid noted, thanks! I should put secret sprite up there XD
Thanks for playing!