Zucas said:
Depends on how much it needs to sell to make a profit. As long as the game turns a profit, it is a technical success.

But I'd assume that the production value of Zack and Wiki was probably not that high, meaning the game probably only needed to sell about 150k-250k to turn a profit. And if we take into account shipments Z&W has probably hit that.

 He basically said it

If: Money Made>Production cost  Then it's a success.

Of course, you need to sell a good deal to do that. Developer only makes about 20% of the actual game.