Romhack of the day: "Castlevania: Aria of Sorrow (Hugh Baldwin hack)"
If you enjoyed CV:AoS back in 2003 on your Gameboy Advance, how about revisiting it with enough changes to make it fun again?
The story is replaced with a continuation of "Castlevania: Circle of the Moon" that follows Hugh Baldwin, the spurned would-be inheritor of the power of the Vampire Killer. The map's the same, but with new weapons, new armour, and some other surprising variations.
I enjoyed it!