I have some games written several years ago in Torque (so C++ engine code and Torque scripts). I'd like to have them in Unity3D. I have searched through the Internet but haven't found anything. Is rewriting everything from the scratch the only way to convert those games from TGE 1.5.1 into Unity? I know that I can import some graphics but I cannot find anything about code.
Yes, it is the only way. Not only do they use different languages, but also different concepts to reason about game logic and different coding practices.