Rexaura is a mod for Portal based on high energy pellets and several new mechanics surrounding them.
A very challenging but very thought out portal mod, just like Portal Pro this mod is a masterpiece of puzzle solving. Was hoping for some more story based ending, but personally that is also forgivable. Did often come across annoying glitch though where I get killed the moment I go through a portal devoid of nearby hazards. Finding the third bonus cake was pure evil, don't ever make something so tedious again.