Same problem. I just installed java and the game still doesn't run on my windows 10 64 bits :/
Viewing post in Can't start MewnBase.exe on Windows 10 (64-bit)
It looks like it needs the Microsoft Visual C++ 2010 Redistributable Package (x64) https://www.microsoft.com/en-us/download/details.aspx?id=14632 (I think dude updated the FAQ to include that tid bit)