I am not sure if I understand the term "game concept" correctly in context of a premise.
A premise would be more of a story thing. Like the classic boy meets girl. And most of the concepts I read are rather mechanics. And ways to frustrate the player. But player frustration is a rather well working concept ( I am looking at you, Dark Souls). And even the silliest concepts like idle games do exist. Cookie Clicker was specifically designed to be a non-game. So I am not sure, if there even is such a thing, as a bad game concept. Because, well, everything that is new is exciting, therefore, if you manage to come up with a bad concept it would be new and exciting and it were a good concept for the novelty alone.
(Oh, and watching paint dry? Seriously? People will use it as an awesome screensaver. Also, would not be a game, but a movie. You woud have to add blow dryers, open windows, use a fan, etc, (but that would be the awesome execution probably))
That being said:
A typing learning game, but the words are spelled wrong.
A game about being invisible in an unlit room.
A match-1 game.
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Examples for previously thought of "bad concepts", to illustrate my point ...
A game where you have to control passports.
A game where your character can die permanently.
A game where you try to score with the ladies. But fail.
A game where you have to read. Lots and lots.