I read a comment on Gamasutra that mentioned the game Soul Bubbles by French developer Mekensleep and how its lack of definite genre and audience limited it to an order-only title exclusive at the Toys R Us stores. I did some Googling to find some interviews and interesting stuff.
I also found this great GameSetWatch interview where the creative director Oliver Lejade discusses how the game came to be. From starting off as a PC tech demo, to becoming an innovative title making extraordinary use of the DS’s capabilities. Here’s a quote on why they had a hard time selling the game to distributers.
You’re saying, “Oh, this is a game about little girls, pink ponies, and you know that little girls are going to buy this,” it’s X number of units are going to go, it’s an easy sell. But when you come in with an original game, that they don’t have any clear reference to the gameplay of something that has been done recently, that has no license, then it’s a very hard sell. And if you have only five minutes? I can’t explain Soul Bubbles in five minutes. It’s not doable — and I made the game.
You can read the interview here: