I recently stumbled upon Project AM2R, a full-blown remake of Metroid II: Return of Samus in 16-bit style. It is an unofficial, fangame project that has been in development for a few years.
From the screenshots and the progress updates, Project AM2R seems to be coming along nicely, as many areas of Metroid II have already been finished. There is even a playable demo that can be downloaded from Project AM2R’s site. The demo itself is pretty well-polished, as the graphics and gameplay are reminiscent of Metroid: Zero Mission (a remake of the original Metroid that was released by Nintendo for the Game Boy Advance).
As I consider some of the 2D Metroid games to be some of the best 2D side-scrolling adventure games ever to be released (especially Super Metroid), I’ll be keeping my eyes on this project. I’d have to admit though, I’m surprised that the project has survived this long without getting the attention of Nintendo, as like with Square Enix, Nintendo religiously protects their IP and shuts down fangame projects swiftly.