Last card?

[Clair de Lune.]

Hello people, im on the playground world and i'm missing one single overworld card.
I've seen every single part of the world, but it seems im still missing it :(

Is it really well hidden or something?

[NoobiK]

It's hard to tell what you have and whatnot. Generally I haven't had problem finding any card in any level. They are big and on obvious places. Look up on ledges. Jump somewhere high and look around, you will be able to spot it.

[creamy jeans]

A lot of cards are hidden in/on the climbing frames. There is also a card near the top of one of the poles near the field which I missed for a long time.

[Edwin]

OHHHHHHHHH I just found the last one
It "hidden" at the RECESS. Near the slide, you know there's a long tube on the other side. There's a card beside the bottom of tube.
Hope this is your missing one.