Use arrow keys to switch packs in the Shop. This game is called Stickman Cards, inspired by a game on Kogama called KogaCards. So you have to buy cards in the shop (You can buy only one at a time) and battle with them in the arena so you can get more coins and if you're lucky you could break the world record for most coins. How the cards work: So if you get a card, it will tell you there power, there name, and there special ability (not all cards have one). The power is the first way the battle compares both cards in battle. The card that has the most power wins (unless the other card has an ability). If both cards have the same power however, then it matters what color the card is (Red beats Blue, Blue beats Yellow, Yellow beats Red, and Purple beats everything.). If there the same color (or if one of the cards are Purple) and same power, there will be a 50% chance of you or your opponent winning. You can see your card's power and special ability on the bottom and your card's name under the picture. The booster pack is the same except it only has good cards and no bad ones like Soldier. It cost more coins though. The showdown mode is the same as regular mode exempt every opponent has their own set of cards and they will only pick out one to battle. If you beat them, you get a lot of coins and a card. It will tell you what the card will be on the selection screen on who you want to fight If you don't have enough money to continue buying cards, then press the start over button in the main menu to try again.
Thanks to King Kuba (on Kogama) for making KogaCards. This is KogaCards: https://www.kogama.com/games/play/8114780/