Starting now this forum will allow concept threads, and prior requirements will be removed. Concept threads are now welcome. The expectation of continuous progress updates and completion will be moved to encouragement of collaboration and feedback. A thread can start with the ideas you have for your project, and it can be taken as far as you want it to go. The emphasis should be on keeping a project open, and sharing thoughts on a project's development. Any sort of SMBX project is acceptable so feel free to try new ideas and explore them in your future projects.
Threads that already exist may continue as they are, but they no longer have the same obligations. Posting ideas, levels, or anything else related to the project and engaging with feedback is perfectly acceptable as a proof of effort.
Creativity and collaboration should now be the bounds for project threads. The only real restriction will be against frivolous threads that fall out of bounds.