I might actually join this if I can become unlazy enough to finish my C++ platformer engine.
Also, if I don't mind mentioning, I think that depending on the language, you should still be allowed to get the code badge and use pre-made engines/libraries/whatever. Things like Game Maker and MMF are technically engines, because they simplify the making of a game. For my C++ engine, it'll require coding collisions, graphics, and audio from scratch. Obviously, using something that's already made (partially, in my case, because I've started making it) for stuff like that should be allowed. I'm certainly not coding graphics and audio from scratch.
Also, if I don't mind mentioning, I think that depending on the language, you should still be allowed to get the code badge and use pre-made engines/libraries/whatever. Things like Game Maker and MMF are technically engines, because they simplify the making of a game. For my C++ engine, it'll require coding collisions, graphics, and audio from scratch. Obviously, using something that's already made (partially, in my case, because I've started making it) for stuff like that should be allowed. I'm certainly not coding graphics and audio from scratch.