Nintendo Game rom hacks are all the rage and heres another for you to digest:

Voidís Blitzarre Adventure, a completed Fire Emblem romhack. While discussing the ins and outs of hacking, some members of Fire Emblem Universe, a Fire Emblem romhacking site, had the idea of attempting to complete a full, 30-chapter romhack in one single week. After the week had passed, the hack was completed. After a few more days of polishing after the week, the hack is now in a presentable state.
Some of the hackers had made ASM modifications beforehand and took this opportunity to implement them in a finished product. As a result, this hack has some significant quality of life improvements, such as being able to press Select to view enemy range on the map and viewing unit growth rates on the status screen, and being allowed to see combat stats when the animations are disabled. Most notably, the hack has added skills, similar to the 3DS Fire Emblem games, into the Game Boy Advance Fire Emblem engine.

full info --> http://www.romhacking.net/hacks/3595/