Novelty ideas are the kind of ideas you do not think of at first, but when put in practice, they become surprisingly fresh and original despite the limitations it wields - a novelty. In this category ranks Oops! All Greyboxes, a recently announced community project led by Remilia Scarlet. The project centers on crafting maps using only prototype textures, for which a resource pack is provided. In doing so, your map achieves an unfinished look, mostly made out of solid colors. Further rules are:

• You can ONLY use the provided textures - no stock textures, no other packs.  That's the whole point of this project :-P
• This is for GZDoom using UDMF and the Doom 2 IWAD.
• Deadline: November 30th 2020.  This is firm.
• Pistol start on every map.
• No slaughter maps, no Terry or joke maps.
• Freelook will be allowed on all maps. Jumping and crouching will be up to each mapper, however.
• Each mapper can submit up to two maps.
• You MUST use long texture names on your maps or they will be rejected  outright.  This is a firm requirement.  When you first do File->New in UDB/GZDB, there's a check box that says "Use long texture names." 

Scarlet aims for "Finished and polished gameplay, and a prototype look."  Oops! All Greyboxes! is thus a project with a look all of its own, its idea indeed a novelty. And hopefully, its execution becomes a success.