If you can download game build (and you can even for web games) you can decompile it with one tool (in our case its GDRE Tools) and than you have all the code, all game assets, everything.
I didn't know that it's soo easy before our game was stolen, when I started to dig into that theme, I tried to rebuild our game from web page, and I was able to do it in 7 minutes. So if thief do this regulary, he can rebuild our game even faster.