Only requirement, has to revolve around all three Spyros.
Just get rid of the () before you post.

~Categories~
Plot: (What main storyline and plot devices would you like to see in a Spyro game?)
Playable Characters: (Which characters other than the three Spyros would you love to play in game?)
NPCs You'd Like to See: (Got any old NPCs you'd like to see again for advice and the like? Or perhaps new NPCs or you own making...)
Gameplay: (What type of game play would you like to play? RPG{leveling system}, Adventure{need specific items to increase your powers} or both? A world that that's on a set path or one where there's a lot of stuff to explore and you get lost looking through all of it?)
System: (If it were a real game what gaming system would it be on?)
Camera Type: (How do you want the camera? First person, active or a camera where you look down on your character from above?)
Homeworlds: (Make up a main world that leads into the smaller realms.)
Levels: (What would you like to see in a level and what kinda of quests?)
Abilities per Character: (Pick a character and think about which abilities of theirs you'd like to see.)
Battle System: (How do you want to play? One character at a time and switch them out because you need different characters for different things or do you want to travel with your whole party out on screen and you pick which one you want to play while the others follow you?)
Main Game Objectives: (What type of things do you want to collect to beat a level and get a 100% for the game? Like Talismans in Gateway to Glimmer or dragon eggs in YotD. Should we bring back the gem system?)
Minor Game Objectives: (What kind of little trinkets should we get for finishing a quest or have to find them hidden? Like the orbs in Gaeway to Glimmer.)
Main Villain(s): (Who do you want back a villain? Or do you want to make up someone new?)
Minor Villains: (What kinda in-level mini bosses or between world bosses should you have to defeat before moving on?)
Extra: (Anything extra you'd like to see in game. Like romance or tragedy.)