During a Pikmin 3 demo, Kotaku got the chance to speak with Mr. Miyamoto. During their conversation, the outlet asked the game designer if he feels like he ever made a bad game, to which he replied with a simple "Yeah."
Naturally, Kotaku followed up by asking him which game that might be. Through a translator, he sort of double-backed on his prior answer, saying: "I wouldn’t say that I’ve ever made a bad game, per se, but a game I think we could have done more with was Zelda II: The Adventure of Link."
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Miyamoto Discusses His One "Bad" Game.