I think there were a few instances where I filled out a section by using what I know and working out the rest by reading writing and filling in what makes sense. Felt like cheating.
The game does feel like all the evidence is there though and i it was fun working it out but it did fell like the game peaked after the first few chapters and then went downhill. The puzzles seem to get lazy at times.
I spoke to soon about Portal 2. I thought I was as the end when I last posted but there's been 2 more chapters.
the end isn't even the end. you haven't finished the game if you haven't played the extra coop levels.