Most of my ideas are inspired by my favorite video game series: The Legend of Zelda, Metroid, Castlevania, Final Fantasy.
When I try thinking of what would be an awesome hack for a game I usually think about taking one of those games, then switching the story, some of the graphics, and a lot of the mechanics from another of those games, and implementing it into the original game that I'd want to hack.
I will use the original Final Fantasy as an example. I would combine a lot of the elements from Zelda and Castlevania NES games, as well as Metroid, into it. One way of looking at it would be to imagine Gargoyle's Quest, which uses various perspectives and mechanics of those games, depending on where you are in the game. There is the overhead world map and the sidescrolling levels and random encounters, and the RPG elements of talking to NPCs for items, quests, etc.
This is how I would change Final Fantasy:
If memory were not an issue, the World Map would still use an overhead perspective and still use the same land. However, the size of the world would be dramatically increased in scale. The World Map would now resemble the Legend of Zelda, with certain areas being unreachable without certain equipment or vehicles, such as an airship or something like the hookshot. The graphics themselves would thus become more detailed, similar to how Infidelity's new Legend of Link hack, which is a hack of the original Zelda, has more detailed graphics similar to Link's Awakening DX.
There would still be dungeons, towns and other areas throughout the map, but they would also act differently. First, the actual mechanics of exploration and gameplay would be more of a Metroidvania style of game. When you enter one of these special areas, be it a dungeon or town, a new map would load, and would have a different perspective. The perspective would a 2-D Sidescroller like Metroid and Castlevania. Imagine how Blaster Master switches between the two perspectives of map and dungeon, except vice verse. Now that I think of it, a hack of Blaster Master that changes the perspectives would be interesting too.
Towns and Villages would resemble those seen in Zelda II: The Adventure of Link and Castlevania II, as well as the retro-inspired game Shovel Knight. Just like a Metroidvania game, some portions of these areas might not be reachable until you get a certain item. An example would be a large building, such as an Inn, where the top floor acts as a Pub, but the player can't go up the stairs to get inside because of his age. To get in, you would need to be able to get atop the roof of the building through platforming, and using something like a Hookshot, or a Double Jump or gliding mechanic. Inside would be more NPCs, where you might be able to buy better stuff like a health upgrade or gear, or get side quests, or simply progress the story.
Platforming and Combat would then be like Castlevania: Symphony of the Night, which I think is the best Metroidvania game there is. The player would be able to get better armor and weapons to equip, which would change your stats as well as how they look. The game would still use the same magic abilities, but how the appear graphically would be changed because of the side-scrolling platforming perspective.
Random Encounters. These would no longer exist. Enemies would appear in both dungeon and world map perspectives, and the combat mechanics would change depending on the perspective. The World Map one would play like Zelda, but use the same stats, spells, and gear, while the dungeons would do the same, except playing out like Symphony of the Night.
The layouts of the towns, cities, and dungeons would be adaption of the original Final Fantasy layouts. If a dungeon in the original game had four floors, there would be four specific sections in the hack as well, and chests that appeared in the original game would also be in those specific floors. The graphics and sprites for these areas would have to use as similar a palette as possible, yet still have some liberty in what would need to be changed, so something like the background walls wouldn't look bland.
As for the enemies, they would actually look the same as well, except they would need to be animated since they would have to move if the game was an action-platformer. In the old games - this is more noticeable in the Dragon Quest games - when a play or enemy would attack a flash of light would appear, paired with a sound effect, before you would see how much damage it had done. Now, those attacks would be animated and adapted so it would look like combat in Symphony of the Night.
You might be saying, this idea for a hack wouldn't work because Final Fantasy had four characters. Well, you'd only be half right. If you ever unlocked Julius Mode in Castlevania: Dawn of Sorrow, or played the Bucky O'Hare game on the NES, you will understand how this would work. In Bucky O'Hare, when you rescued one of your friends you could switch between the different characters, who had different abilities. Julius Mode in Dawn of Sorrow is a second campaign that uses the same map from the game, except you play as Julius Belmont. In this mode you eventually come across Yoko Belnades and Alucard, who all have different abilities, like Alucard's bat form.
The only negative aspect of Julius Mode is the absence of certain gameplay mechanics and features. While these changes are intentional in Dawn of Sorrow, as a way of making the game more challenging and adding more variety to the way you approach the game, in context with the idea for my hack, there would be no absence of features and mechanics. Characters would still acquire new weapons, armor, and spells. There would still be items likes potions and phoenix downs. The characters would share the same health pool, as well as a mana pool.
So what do you think of this concept? What would you add, or for that matter, what part of my idea would like to see changed back to resemble the original game more? Let's keep discussing this and hopefully make this idea that much better, that much bigger in scope and ambition.