For the 23rd anniversary of the original Metroid, ROM hacker Infinity's End has created an extensive graphics hack for the NES rom that completely overhauls all sprites to look much, much better and closer to the art style in the sequels.
In addition, there's a new subscript for the game for the FECUX 2.1.2 emulator called the Lua script which gives Metroid many features from newer titles including a mini-map, pause screen map, start menu to toggle items on and off, a timer and more changes.
You can download it here: http://metroid-database.com/
Watch it here: http://www.youtube.com/watch?v=qMaiRvphfq8&feature=player_embedded
I've confirmed it will play perfectly on the powerpak, but the powerpak will obviously not use anything from the Lua script. Still, playing this hack on the Powerpak is a recommended experience for all Famicom players.
This is a graphics hack only; layouts are not altered.
The hack is kinda 'meh', but the LUA script is awesome. That's to be expected from Neill Corlett, though ;D
I actually think the custom sprites are fantastic, espically the suitless samus and the three bosses. The game now looks like a late generation NES game rather than a early-mid gen game.