unknown file without extension file [UnityFS]

[reksu66]

do anyone know what kind of this file?
how can I view inside this file?
if its contain resources how do I access to it?
Is there any guide on how to open or recognize this file?
I provided some files example at the below
Thanks

https://drive.google.com/file/d/1utbYMguL7NduUFtHcU0s0tXiN0qc-WVj/view?usp=sharing

[aluigi]

Unity files must be opened with the relative tools:
viewtopic.php?f=17&t=12

Please next time remember to specify the name of the game too.

[reksu66]

Unity files must be opened with the relative tools:
viewtopic.php?f=17&t=12

Please next time remember to specify the name of the game too.

Noted and thank you so much admin