@Anonymous
I did a simple test flow, and it's working fine. Please note:
-each approver's email addresses must be defined in your Tenant Azure AD.
-by using this approach, when dealing with multiple approvers you need to wait for everybody to answer. THere is another approach to read responses before everybody answered
-comments are optional. THis means when iterating through the 'Responses' array, one or more responses may not include this attribute
Here you are my test flow, I just added one responder, but the concept is exectly the same as if you add more than one

Now, 'Apply to each' expanded:

In my test flow I took some design decisions on my own:
-I store responses in an array variable modeling them as objects, so I store comemnts, responder, answer and date time. THen I transform this array into an HTML table.You can add this table to your emai notification body, just remember to add a 'Send an email' action block. But, if you prefer you can add only responses to your array variable, or model your array elements as strings instead of objects, and then use join() WDL expression to combine all elements from your string into a single text.
-I do not to read responses if the result is 'REjected', but you can read responses and send a notification no matter the result is.
THe possibilities are almost endless
Finally, I also verified it's working fine both if responder add Comments but also if he/she decides not to add them. As I mentioned before, I am using a single approver, but it works the same for N approvers
¡Ánimo!