Honestly, it's a lovely idea but the execution is lacking. There are way too many stickers to cycle through, there's no indication that you need to click the rats up top, and the only way to upgrade requires you to get the right sticker. I'd suggest that instead of making the sticker increase in price every time you click it, maybe make it every 5 times, or add a shop where you can buy stickers at different prices, and adding multiple orders would be very beneficial especially at the beginning of the game.