It addressed minor stability issues common in the v0.9 early access branch.
The game was much smaller than it is today, featuring roughly 20 characters and 100+ skills. How to Handle the .rar File Soulstone.Survivors.v0.9.028e.rar
In most cases for these archived builds, you simply extract the folder and run the Soulstone Survivors.exe file. It addressed minor stability issues common in the v0