Here is a summary of a few updates that have been released since Steamworks Multiplayer was added. The first one added multithreading support for Steamworks Multiplayer, which improves performance and reduces latency for multicore cpu's.
Also, I've rearranged and renamed a few of the game modes to reduce confusion and make things more meaningful. I've also eliminated the extra "survival" submenu to reduce the amount of selections needed to start the game. Here are the game mode name conversions:
Classic A Survival -> Classic A Mode
Classic B Survival -> Classic B Mode
Enhanced Survival -> Survival Mode
Blitz Survival -> Blitz Mode
Please note that any achievements obtained for the old game mode names are automatically converted so that no progress is lost.
I've also updated the Blitz Mode info screen to better describe the way the mode is supposed to be played and fixed the erroneous text of how many enemies need to be destroyed per wave.
To make sure you have the latest update, the version number is 1.12.7.4