Thanks for taking the time to read Traumatiser. They actually have released a playable demo here: Renegadez Update and Playable Demo
Unfortunately, the Reddit Gunz Community is very small, and they haven't had much luck reaching out to the old Gunz community, which is why I thought I could share it here. As for the reskinned mansion map, they wanted to recreate a few of the old maps as tribute to the original game.
Here's Kazuma trying out an older version of it...
Kazuma Trying Out Renegadez
As for the donations, it could easily just be a friend of the developer. I have also donated as well, although I am working on music for the game. Not actually on the development team though, I just offered to help out.