My suggestions: (I might work on these in the coming weekend)
Add an ingame link to the tutorial as well, in the main menu.
Make the chat be a togglable overlay on the right side of the screen, removews the need of sidescrolling (And many players might not even notice the chat exists right now)
Add more help overlays, preferably to the main menu and the battle screen.
Make it so the cards in hand doesn't move around at all, all card places are static until played. New cards appear on the first empty spot. (This could be an option)
Also, the card images in the booster shop does not have any card text, so that needs to be fixed.
Pressing space scrolls the whole page down.
The first 3 are important for any new players, the 4th makes it a bit less confusing, the 5th and 6th should be fixed regardless.