The description of the game jam says that a developer can submit more than one game so does that mean that if a developer submits more than one game made by Yahaha studio then will the developer win the prize for participation for all the games submitted? I guess many people have this question on their mind.

That's a great question. It will be one payment only for the Yahaha participation prize. Also, if a game is made by a team, the prize is split between the team members