This hack is a combination of three independent hacks.
The author of this hack only claims credit for the hard work combining them together.

Locate a copy of the US version of the Metroid rom and apply the patch.
LunarIPS is a great tool for patching: http://www.romhacking.net/utilities/240/

All credits go to the below listed hacks and their individual authors:

Metroid + Saving (v 0.3) - snarfblam: http://www.romhacking.net/hacks/1186/
 - Minimap
 - Savefiles
 - Beamstacking
 - Better icebeam and bombs

MDbtroid - Infinity's End: http://www.romhacking.net/hacks/1219/
 - Nicer titlescreen
 - Nicer endings
 - Updated run animation
 - Updated player sprite (suited and suitless)
 - Updated enemy sprites
 - Enlarged and updated Kraid and Ridley
 - Updated Mother Brain
 - Various updated tiles

'Roidz - DemickXII: http://www.romhacking.net/hacks/1240/
 - Nicer background tiles
 - Animated lava, doors and elevators
 - Animated corridors
 - Animated Norfair (Ridley level)
 - Animated Tourian (Mother Brain level)
 - Various updated tiles

/dACE a.k.a Nitendo