There are 10 cards in total.
The numbers on the map correspond to the card numbers.
Cards are often at dead ends separate from the correct progression route.
(doesnt exist on boss stages that use teleporters)
Be careful as the second and last cards are easy to overlook.

Card 01
Destroy a large rock with bomb to reveal a card.

Card 02
Destroy a regular rock with shots to reveal cards.
Its easy to overlook, be careful!

Card 03
Located at the dead end of the highest altitude point in the first half.

Card 04

Card 05

Card 06

Card 07

Card 08
If you fall into lava, die instantly.
The upper scaffolding is only for the return trip :(
Be careful!

Card 09

Card 10
The final card is in the last room.
The cards move up and down through the gaps in the ceiling.
Do double jump to get the card when the card altitude is low.
This card is also easy to overlook.

Even if you collect all the cards, the achievement will not be unlocked at that moment.
The achievement will only be unlocked when you return to the title screen with 10 cards.
You can check the cards you currently own on the title screen.

If you die and load after get a card, that card is not lost!
You don't have to go to pick up the same cards again.

I hope this guide helps you :)