At Pocket Gamer Connects San Francisco 2015, Scott Stevens, founder and Creative Director of 2Play Games, gave a talk on coming up with "winning" game concepts.
He started by pointing out that "you need to move on from just 'I want to design a fun game'", and said you need to focus on what makes your game actually fun, rather than your own idea of what fun is.
Stick to your guns
Stevens also suggested that developers should "be player-centric", and ignore what marketers and publishers say in favour of listening to the people actually playing the game.
Finally, he said that you shouldn't take on board any suggestions that don't match what you intended for your game, and that you should "make your game true and defined for your vision."
You can see all our videos from Pocket Gamer Connects San Francisco 2015 in this YouTube Playlist.