I know I’m not involved in this particular competition and it might not be my place to speak on this.
But, it’s not really fair to give your contestants a strict deadline for a “FULL-OF-EFFORT” game when there’s nothing on the line. What’s the point of a “test” when there’s no use for the results. Plus, did you realize that 2 of your contestants are also in other competitions at the moment because you said that the tourney would start in July, and I can imagine that’s pretty difficult to manage.
Literally two of your contestants had to dropout because of this, it pains me to see that because I loved the idea of the Coder King since the original, it’s a nice thing to do while Makecode doesn’t have any official game-jams going.
But put your self in the perspective of @randomuser, you expect to have 2 weeks to make a game and a competition you basically pre-ordered is asking you to make a game in 10 days just because. It’s simply not kind to ask for such a task, I understand that some contestants are totally cleared to complete in your “diagnostic challenge” but maybe ask beforehand which of those players are available before making such a jump in change.
Good luck to @Taser and the remaining contestants 
!