Thanks for the feedback!
Yes I was aware of the few mistakes in the concept, I kept the two different spades because I wasn't sure which one I preferred more.
And I'm still not really sure how I should design the whole deck of cards. My first option was to have different colour jelly monsters for each suit indeed.
Most decks have like 55 +/- cards in it. Creating a different illustration for each card is an option, but I'm afraid I will run out of ideas to have the monsters mirrored, interact with the mirrored monster and have the symbol interaction in it. (heart 5 is a great example of the idea, last image)
my second option would be creating a unique illustration for each card in a suit ( A, 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K) give them all one colour and copy the illustration for the other suits but with different colours and symbols, but I'm not sure if that would come off as laziness.
(also the numbers will be redrawn, just filling spaces now for the looks)
So any tips or help would be great!