Welcome. Thanks for considering if it was okay or not! We are not sure about how legal that is but now that its leaked people have it! Really exciting.
I thought twice before giving you guys these things, I don't wish to give you trouble!
Were you able to compile it?

We are not able to do it already since it needs proprietary software, but it's not THAAAAAT nightmare to do so. It seems like they are using some sort of GCC to compile all the C files.
There are many, MANY unused things here!
+ it's reusing assets from a previous game, probably NBA Jam (Even unused NBA Jam dialogs are there I believe). There are even the family addams music in it (

) and other awesome mid files that I don't recognize where they are from
+ There are files that show the hexadecimal overlays for, I think, it belongs to the hud. (Like the weapon selection) Interesting is that are unused overlays, like an unused weapon known as TomaWeapon
+ The build is 49, different from the Beta trailer's 33 build (
https://youtu.be/Dn7YKp0X8Q0 ) and some of the audio I heard in the source code also is in the alpha video.
+ Judging by the files, I believe that the enemies were able to give you a sound cue if they find you. (The human enemies have voice sounds like "I FOUND YOU")
I think something big can come out of this!