Javascript is so fucking shitty that they had to write a compiler to an intermediate virtual machine and a translator from the said machine to javashit so that they could write the game in C++ and compile it with this humongous chain of crutches to play it in a ``browser''. It turns out writing a game and a compiler in C++ is preferable to touching this javascript yourself. Language has to be really, really, really shitty to make people prefer C++ over it.