Game Design Novice

Ok so this game is hopefully going to be made in Playbasic.

This game is going to be like The Legend of Zelda: Oracle of Seasons.

The player is going to have several puzzles to do in order to progress to obtaining the items and beating bosses.
The player starts with nothing and must find a suitable weapon and armor. He is just a farmer.

The main character (player) must kill the leaders of the assassin guilds that rule the world and must kill all of the kings
in a dimension just like the main world. Only everything is different. The main world only experiences Summer and Winter,the
dimension only experiences Spring and Fall. The player must reunite the worlds after killing the leaders and ridding the dungeon bosses of life.
The world will have all four seasons, the main world had forgotten about the seasons in the dimension, and dimension people forgot about main world
seasons.

It turns out that when you thought you had killed all the kings and leaders of the assassin, one of each managed to escape alive. You other who you defeat two times previously during your quest was helping them. You must kill the remaining king and assassin and your other in the same battle. They fight you at the same time. Other objectives exist, but will be announced after i figure out how to start making the game.

I got no sprites or anything. Any sprites i can download to use in the game will be apreciated.

First question: how does the title tie up in that story (or should I say "objective"? ;) outline? In other words, what is a "darkling" and where does it appear in your story?

Not being a zelda fan, what kind of game is this? An adventure where you walk around interacting, fighting and solving puzzles? isometric tilemap view?