Making a sequel for a jam game and thinking to go for Extra/Casual format

One of my earliest Game Jam games was Medic Mayhem. I have been wanting to make a sequel for it a long time and now that the theme suits it little bit, it feels like perfect opportunity. However using a "ready" game as a starting point this feels like little bit of cheating. That is why I am thinking about the Extra format.
What do you guys think?
