They Wasted a Perfectly Good Plot

""It's Superman fighting twin clones of Hitler. HOW DO YOU SCREW THAT UP?!""

- Atop the Fourth Wall on Bearded Idiot: At Earth's End

You feel like you've been given the first three chapters of a story, a story that you really would have liked to see to its conclusion, but either a) it's on a whole different set of rails now, or b) while you do see it to its conclusion, it ignores the intriguing possibilities you'd hoped to see. Note that this does not include a plot/idea you like not being a well-written story/well-made game/etc.

Compare Aborted Arc and Worse Than It Sounds. Not to be confused with Offscreen Moment of Awesome, where the thing you would have liked to see did happen but they never actually showed it. Often results in Alternate Continuity Fanfic Fuel. For this trope applying solely to characters in the plot, see They Wasted a Perfectly Good Character.