 They also dropped the introduction of the Rat Man, a character who left the messages in the maintenance areas, to avoid creating too much narrative for the game, though the character was developed further in a tie-in comic "Lab Rat", that ties "Portal" and "Portal 2"s story together.According to project lead Kim Swift, the final battle with GLaDOS went through many iterations, including having the player chased by James Bond lasers, which was partially applied to the turrets, Portal Kombat where the player would have needed to redirect rockets while avoiding turret fire, and a chase sequence following a fleeing GLaDOS.Eventually, they found that playtesters enjoyed a rather simple puzzle with a countdown timer near the end; Swift noted, "Time pressure makes people think something is a lot more complicated than it really is", and Wolpaw admitted, "It was really cheap to make [the neurotoxin gas]" in order to simplify the dialogue during the battle.