We have just released a new build of the game (v1.1.8664) that increases performance across all platforms (Win/Mac/Linux) and includes some minor polish and bug fixes as well.

New:

• Added winter holiday props and snow effect to the main menu backgrounds
  

Updates:

• Updated the game's lightmaps on all levels
  

Optimizations:

• Updated the game's engine for better performance across all platforms
  
• Added 64bit and Metal support for Mac (on supported systems)
  
• Updated our shader cache to reduce GPU work at runtime
  
• Tweaked graphics quality Low setting for better performance and particle visuals
  

Fixes:

• Fixed misc. minor bugs