I'm a world and a half through now. Still really liking the coin gimmick, especially when there's coin treasure troves in hidden areas, but man, those halfway castles in all of the NSMB games are 100% interchangeable and unmemorable. I'm very done with them. Also the world structure in general is wearing on me. I'm really glad NSMBU changes that. Hopefully they don't go back to this structure ever again. But, while in the level, this game is fun.