itch.io

You could add some audio onto the opened pack scenes such as a card or normal shop ambience just to add some realism, add some audio for actually opening packs, The packs seem to be for the same "set" maybe you could make it more obvious which is for which set as well as separating the cards per their set/ pack, have named cards or just add images to show variation name the cards more than just their colours and have a total set of cards for each pack and track it such as 10/102 cards and so on under each section, So you will have 3 sections for the 3 packs, listing the cards in the packs, and the total amount of cards. Also changing the background to be more than just a solid colour throughout the entire game.

Positive things about the game:  You clearly understand the purpose of the game and it has good management and random chance of the cards spawning based on rarity (Could this have been done more visually than assuming the player will catch on?) The audio feels like an old Pokémon game but with its own unique twist, the gameplay is smooth and doesn't cause issues. But wont this get tiring as a game if you don't have to work for the pack opening? I know AI Battle hasn't been implemented yet but I will recommend 3 skill levels (for the 3 packs)

The connector for the 4 different pipes doesn't match up, it should fit with the other parts. It's very subtle and I cannot change it without changing the entire asset pack.

I suggest when you get stuck to flip this pipe a few times to see if it's wrong or not. I can see on another comment you've figured it out but I thought I'd offer some clearance as to why.