Here is a guide with all hidden card locations and cheat codes, which is updated for the latest version, 0.50.
Location of All  Hidden Cards (Special Renders)
Note: This guide will be updated when new cards are added.
All Hidden Cards
How to View Them
Cheats Guide & FAQs
How to Cheat
FAQs of Cheat Codes
Q: Do I need to re-enter the cheat codes when I start a new game?
A: No, if you have entered a cheat code once, it will be active even if you start a new game.
Q: Are the cheat codes permanent? Do we need to re-enter the cheat codes when we load an another save file?
A: Cheat codes are permanent. When you enter a cheat code, it will be active in all save files you will use. You will only need to re-enter the cheat codes if you delete the persistent file in the game’s save folder.
Q: Will the cheat codes work in future updates?
A: Yes. All cheat codes will work seamlessly with all future updates.
Finally, If you’re still looking for cheat guides, please check out the following articles: