How many new levels? 28.
What Characters will you play as? Chell, Rattman, and a Male test subject that is "found."
What are some new tools? Multiple things such as Wrenches, and Wirecutters.
Copyright? It said in the rules that if I use the Source Engine for the mod, it can be worked around.
Free to play? This is a free-mod.
New Voice Acting? Yes. Samples will be uploaded soon.
Fully changed design? Not fully.
Why not only the Portal Gun? The Chell storyline only has a Portal Gun. The Rattman chapter has the crowbar and other tools, because he didn't have a Portal Gun in the comic. So I couldn't have one in the storyline either. The Male Test subject found by Wheatley, he has a One-Fire Portal Gun
If you have any problem please feel free to comment, but these are the answers to most basic questions.