One that comes to mind is how Grundislav is pitching
Lamplight City: "A detective adventure where it's OK to fail" (
as PC Gamer phrased it). It highlights an innovation or distinct feature that sets it apart from the genre as a whole.
I found that the ca. 80-word limit meant having to be very choosy about what to include and what not to include. I had two "gimmicks" in mind that I wanted to mention, but decided to leave out for the sake of brevity (as a reminder, this was the game where you're a student investigating a disappearance at an Oxbridge-style university):
-You start the game playing as the candidate who disappears, and the choices you make in this intro will influence elements of the mystery later on. In this section you also designate the character you'll play in the rest of the game (you ask one of the others to look after your stuff while you step out, and that person becomes your character).
-The game takes place over a full academic year (three terms), with the big climax taking place at the
May Ball. (I always like it in games when you get to see familiar locations dressed up in new ways, and here you'll both see them change through the seasons and literally dressed up for a big ball.)
(Both of these gimmicks would complicate development immensely, but since it's just a pitch for a game I'll probably never make, who cares?)