Compare two "runs" for different instructions

Hello,

I have a software that takes an input and gives an output. I want to check what instructions are run for a "good" input and what extra instructions are used for a "bad" input so that I can have somewhere to look.

What's the best way I can do this? Is there a plugin I can use?

(Also might be related but, in this software the first and major module I see is just "ntdll" instead of the program itself which is what I'm used to. For example, as soon as I do anything in the program, one of the first instructions is `call ntdll` and then all the magic happens in there and I get an output. The only other piece of software that I reverse engineered (im a noob) had the program itself and all its instructions like e.g. value comparisons as the majority of the memory address but it's not the case here.)

Thank you!