Heres a page that tells you what a wba file is. Its a type of compession format:
Don't know if you could decompress it with anything else
Have you tried looking at this site for themes?
I havent used it, though it seems to have alot of stuff. Though it seems to come down with a .exe... Though if you had some virus testing software first since i haven't tried it before, it could be cool! I'm sure its fine
For instance, theres a section on games
I Hope this helps