The Mine at Krytos Hills - Solo Module

This feels like it was written by someone very familiar with D&D in general, but somewhat new to 5e. Theres a few mechanics mentioned and referenced that aren't actual things in 5e.

Spoilers ahead

Awareness tests aren't a thing. I assume its equivalent to perception checks.
When you fail the "awareness test" you have "disadvantage against the rat" which doesnt make a tone of sense because you weren't doing anything to the rat. There was no roll you were making against it to give yourself disadvantage over. This should probably be "If you fail the rat leaps out to attack you and you are suprised.", that or you give the player disadvantage on the initiative roll, which doesn't really come up in 5e but seems closer to what you wrote already.

Also Tests in general aren't a thing. There are saving throws to resist effects and skill checks to try and do something. Theres an important difference because the player might have proficiency in...See more Athletics(Strength) checks, but not strength saving throws, so its important to actually clarify which its supposed to be. You can kind of guess based on context but even then the checks should be assigned an actual skill in case the player is proficient.

Theres a few other cases where tests or "listening checks" are mentioned, which arent 5e mechanics, but again you can sort of guess based on context clues.

For an experienced DM none of this is an issue but if you're a new player it might seriously trip you up.