The ideia of two different secrets, one for getting all the cards, and other for not dying is definitely a nice ideia, i also would like to suggest maybe making one of the secrets be having to grab all the cards of the game on a specific amount of time, instead of having to grab all the cards without dying.
And thank you for hearing everyones opinion, its really cool seeing a developer taking constructive criticism , keep up the good work!
Also, i'll keep the secret ;)