Tales of Kenzera: ZAU

The game does a great job of showing you how many of these are in each area and they are marked with a mask icon (check the legend with Y to see which one). If it is greyed out, you found that echo. If it isn't, you were close enough to see it but didn't collect it. I only had one or two cases where I collected the Echo and then died, so I needed to re-collect it. Otherwise, the games saves so fast you should be good! Here are maps of all the area:

Wanderer's Pass (3) and The Buluu Caverns (3):


The Great Cliffs (3):


Ikakaramba (4) - no echoes in the mines below the screenshot:


The Drowning Swamps (3):


The Wildwood (3):


Nature's Crown (3):


Ember's Spring (2):


The Searing Sand (3):


Mount Itshoka (2):


The Enduring Rite (3):


Note that you can fast travel around the map up until the Point of No Return after Act III. The game is very clear about that point, so collect away until then!