Cave Story is a modern classic. Sadly, many people still haven't ever played it, even though it's been released on WiiWare, DSiWare, and the iTunes App store. That's probably partly due to its retro look. It's hard to generate hype for a new (to retail) IP that, at first glance, looks like a game from the '80s or '90s.
Enter Cave Story 3D, a re-imagining of the original title, made specifically for Nintendo's newest portable console, utilizing the "newest"-looking graphics available on handhelds today. Supervised by Cave Story's Daisuke "Pixel" Amaya, the spirit of the original title remains fully intact in this enhanced port. In many ways, this is the version of the game that Amaya-san always wanted to make.
Any questions relating to Cave Story's quality have been answered several times here at Destructoid. The questions remaining to be answered in this review are: Is there enough new stuff here to warrant a re-purchase for those who already have the game? And out of all the available versions of Cave Story on the market, is this the best one to recommend to new players?