I've read every single post about the game not launching.
Tried EVERYTHING and still get :

Failed to start game
(missing executable)
^^ Steam

This has never happened to me before.

Now dont start posting : Did you do....blah blah , YES I DID.

Also because i feel good today i'll even show you the step by step screenshots i took :

http://imgur.com/a/r7TKL#3

From going to the store page and installing to browing local files and finding a empty folder.

Try to DL game client form panzar.com and overwrite client files downloaded through steam.
I had similar problems with other games, where steam client just let me know that game is missing files, and they will be downloaded next time. I never get into this "next time"...