checkers
Explanation
The Joke
The comic has a caption reading: "Nobody appreciated my invention that transformed all games into checkers." A person is shown excitedly holding up a device and declaring "Guys! This is a gamechanger!" to an unimpressed audience.
The Humor
The entire joke is the pun on "gamechanger." In common usage, a "gamechanger" means something revolutionary and transformative. But in this case, the invention literally changes games -- specifically, it changes all games into checkers. The word is being used in its most literal possible sense, but the result is the opposite of revolutionary: checkers is widely considered one of the simplest and least exciting board games. So the inventor's breathless enthusiasm ("This is a gamechanger!") is simultaneously technically accurate and deeply underwhelming. The audience's lack of appreciation is entirely warranted -- who would want every game turned into checkers?
The votey ("Aren't you ashamed?!" / "Yes.") suggests even the inventor recognizes the pointlessness of the creation but went ahead and made it anyway.