Mysterious file I need to make readable

[FryEmUp]

Heyya folks of the internet,
I've recently been attempting to mod a pretty unknown card game which is pretty dear to my heart.
Having near to no experience with modding I've been kinda struggling with it... I only managed to locate the folder containing the game files as well as understand the global structure of the thing.
Everything is fine until I try to read/modify the actual game files... They have no extension and, when opened with a hex editor, don't make sense to the average random guy. The only thing that isn't incomprehensible is the first few words : "UnityFS 5.x.x.2017.4.4f1" or something along those lines.
Trying to learn a bit more about it, I tried googling UnityFS which only lead to websites talking about the unity flight simulator...

Do you guys have any ideas as to how to make those files readable and modifiable ?

Cheers,
Some random guy.

PS : I'm posting here because the encoded files are 2D assets for the most part. I hope this is relevant.

[wansf]

goolge AssetStudio and here u go

[FryEmUp]

Thank you,
I'm assuming that you're referring to the github project with that name.