I just checked the two developers diaries included in the package. They actually aren't anything special: if you followed Vince Twelve's blog as he was making the game a few years back, you would've seen them already. In fact, I bet they're both still on youtube somewhere. No puzzles are solved in it, and at worst, you see 2 sections of the game with two of the playable characters. Perfectly safe to watch if you so choose.