Requirements: a computer capable of running Source engine games, Source SDK Base 2007. If installer doesn't work as supposed, uncompress it manually to your 'steam/steamapps/sourcemods/' folder.
Lot of work has been done to improved the learning curve, more coherent puzzles have been added.
A couple of serious bugs has been fixed: energy balls not able to hit bot instances and a player speed decrease after reload.
New features: stats tracking, gel doors, dual maze puzzle.