Sounds nice, I've already got a puzzle game idea in my head

But I'm not sure if removing the time limit is the right thing to do.
Will there be any finished game without a deadline?
Where would be the excitement?

And personally... I don't care about winning. For me the wish to create a good game within the time limit was the actual challange and source of fun and motivation.

Also I'm usually not a fan of these "just do any type of game" contests without any specific task but in this case (just around 3 persons) giving strict rules won't lead to good results.

On the other hand, in general tasks like "make a platform-run game" are a bit too strict in my opinion.
Something less specific like "create a platform game" would be better.
It gives a target but still leaves a lot of freedom for the gameplay and idea of the game.