I'm involved in designing a custom deck of playing cards which is primarily intended as a language learning tool for children. The cards are divided into 4 suits. But rather than having numerical values, each card has a different word and a picture illustrating that word.
How about adding different symbols to the cards; this could then allow them to be used for a Uno-type game? The symbol could also be used for set-collection games (such as Rummy); collecting same type of symbol; same-type by color; "runs" of different symbols and so on. Aside from that, rules from story telling games like "Once Upon a Time: The Storytelling Card Game" could probably adapted for this deck.
EDIT: If you add some pictures to your posts of example cards; you might get more inspiration from the community!