Well depends what you mean? How many offensive players really scare you?
What do you define as a game breaker?
The "game breakers" in the NFL imo.
RB - Johnson, Bell, Elliot, Murray?, McCoy? (only if 100% healthy... not common)
WR - Jones, Green, Evans, Brown, Cooper?, Beckham?, Hilton?. Bryant?, Nelson?
TE - Gronk, Olson?, Reed?, Graham?
That is about it for guys who i think deserve particularly special attention. Yes there are other very good players but these are the guys that change the games they are in by their plays or actually opening it up for others.
Really only 8 guys IMO are for sure no question guys who are game breakers that make you change what you do on D entirely. Of those maybe 1-2 has the impact Gronk does so of course you will feel it when he is gone.