Developed by Firemint, the game has players using touch controls to navigate a busy airfield and land incoming planes. The DSiWare version contains all of the same content of the iPhone application, as well as an additional snow-covered level.
Nintendo allows $2 games on DSiWare; they chose to go for $5.
Yeah, Nintendo can limit the price range if they feel the developer is going too low/high (e.g. B+ wanted Plättchen to cost 2000 points, Nintendo forced them to go down to 1500 and the market forced them even lower) but the developer still gets to choose within that range. I doubt Nintendo would force FC to be 500 minimum because it just doesn't have as much content as the other 500 point games on DSiWare.
Nintendo allows $2 games on DSiWare; they chose to go for $5. This game is worth $5, though, if you don't have an iPhone or iPod Touch. It's one of the best pick-up-and-play casual games I've ever played, though the controls may suffer a bit in the transition to a stylus-based system.