First of all massive thanks to the community for reporting issues with the game and helping us to troubleshoot them. Thanks to everyone's collaboration we were able to resolve some issues and make progress on others.
Save Game - Resolved
There was an issue with the game not saving correctly through Steam Cloud for some people. We believe that of this morning the issue is fixed and the game should save correctly for everyone now. Please note that the game uses an auto save system. Once you back to the game's main menu there should be an option 'Continue Game' is you have saved progress.
No mouse input - Resolved
If the game is unresponsive to mouse input then you probably don't have VSync enabled. This is a setting in your graphics card driver . You can enable this through the Graphics setting in the Control Center. We are looking into forcing VSync from within the game, so no one has to change this manually in the future. It might also be worth updating your graphics card driver.
Game doesn't launch - Work in progress
This is a bit of an odd issue, that a quick google search revealed is a mysterious issue for quite a few games. The main problem here seems to be a missing / corrupt / inaccessible MSVCP110.dll This file is usually part of Windows and is used by many programs. As a first step we have included the 'VS Studio 2012 - Distribution' as part of the game install. From what I understand this should be done by Steam automatically and not require any kind of manual install. Even with a re-install of the DLL the game still does not launch for a small number of people. We keep investigating the reasons for this.
Sound dropping - Work in Progress
The music seems to be cutting out for some people. We are still looking into the reasons for this.