Metroid II: Return of Samus was originally released in 1991 and a fan-made remake was released as a free download on PC this year; Nintendo has officially filed a DMCA takedown notice against the website that was hosting the game.
The developers behind the remake named AM2R were planning to release more updates however, no details about what these updates might be were ever revealed. The future of the remake is now extremely uncertain.
AM2R featured enhanced visuals including full color and was created in honor of the Metroid Series 30th anniversary; Nintendo however has done very little to celebrate this milestone for one of their most loved and well-known series.
Nintendo officially re-released Metroid II: Return of Samus for the 3DS Virtual Console in 2011 for $4; it’s highly unlikely that the company will allow a free fan-made remake to exist as they’re selling an accessible version of the game.
The next game to be released in the series is Metroid Prime: Federation Force which will be released later this month or Japan and North America and in September for EU and Australia.
There is no way of knowing if AM2R will have a future however the developer did have future plans for the game.