The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
^^ This actually sounds pretty interesting, even worth of its own (sub)trope, since if even the developers, who basically created the challenge and thus can alter it at will (well mostly), have trouble beating it, there's something wrong about their sense of gameplay balance.
I mean if you made the boss or anything too hard for you, why don't you Nerf them?
I don't think there is anything specific for that, but I agree it is an interesting idea. Will probably have a hard time getting it through TLP though due it's potential overlap with things like That One Level, Nintendo Hard, Harder Than Hard, etc. etc. May be simplest just to include the creator's admission in an example on one of those pages.

For example: in the manual for the original Rise of the Triad the description for NME says something like "Even we have trouble beating this guy."