7 Days in Hell is a mocumentary that is supposed to air on HBO soon. At first when I saw the trailer I was expecting it to be a parody trailer for a fake movie, but it's actually real and will be airing on HBO. It stars Andy Samberg and Kit Harington who have a 7 day tennis match. Not sure about it, but it does look like it might be some fun.
Here's the trailer: https://youtu.be/RURGgFuf7c8