Since this game is still W.I.P and this is my first time using Itch.io so how do I update my game when a new version come out ?
Do I just redownload it or something ?
Exp meeting one of their kin:

It shouldn't matter whenever you replace all the game files, or just extract it to a different folder.
It would matter if scav had its save files inside its game folder (I haven't played in quite some time, but I don't think scav saves anything, right?). Then you would need to move the save folder if you extracted the updated ver somewhere else.
Though, as someone pointed out, itch has a client you can get with updates! (first time I hear about it lol)
itch.io has its own client which i find tiny bit unintuitive to use for browsing random games, but is amazing if you use it as launcher with auto updates
https://itch.io/app