Portal: Prelude, as its name states it, is an unofficial prequel to the game Portal. Its story revolves around the pre-GlaDOS epoch, even before she was plugged in. At this time, test subjects were monitored by real Aperture Science employees, whose work was tedious, lengthy and repetitive. This is why they decided to build a great artificial intelligence that could both replace them in these difficult tasks, and also take responsibility for many other tasks within the complex and compete with Black Mesa's superiority. All employees of the Aperture Science complex are now eagerly awaiting GlaDOS. Maybe even a little too eagerly, as the upcoming events will tell... This game is totally free. It offers a bit more gameplay hours than the original Portal, with 8 chapters, 19 test chambers, 48 challenges, 6 advanced maps, a brand new storyline and more than 400 lines of english speech with dozens of subtitles translations.
This mod do not deserve 8.6. It should be 9 at least. Also I can't understand persons who gives lower than 7. You can't give a low score for a game for its hard. If you don't know how to play, dont play any portal mod. Thats all.
Also makers of this mod first language aren't english, so you cant blame them for they are terrible at voice acting. This mod includes orginal ideas, orginal gameplay, orginal chambers, orginal story. Also difficult is not very hard for a person that he knows how to play portal. OK maybe hard, but not very hard. You should be patient. I like this mod's musics. They are relaxing me.
About this mod, you should have to play.