So... it's been a while, right? I'm sorry that I haven't been able to update the mod in a while. I have recently reset my laptop due to it freezing out of nowhere. It's been crashing and such ever since my last encounter with "Po". I've backed up the "broken" version of Portal though, so I still have to sort all of those files. Anyways, I actually found some more info on what Dead Dev Games is!
I was looking through some online forums on what this version of Portal could be. Although not the same game, someone else apparently had a broken version of Guitar Hero 3: Legends of Rock on the PS2. The person (who goes by "Slasher327") goes on to say...
"The first thing I noticed right off the bat was that the only logo that appeared was dead Dev Games, no Activision or anything. Also there was no music playing throughout the main menu. I tried out the song Talk dirty to me and there wasn't any music playing throughout. Just tapping noises. It weirded me out"
So it seems like Dead Dev Games have created other strange versions of games other than Portal... why they did, I still don't know. I do aim on figuring out the reason behind the creation of these games... maybe they created more games than the ones I mentioned?
I will update the mod once I get all of my files sorted out, so expect to see an update some time in the future.