So after spending a lot of time playtesting the card zoom, I didn't like it. Having to be taken away from the match screen every time a card was tapped proved quite annoying and detracted from gameplay. The position of the ability options being constant as opposed to be positioned relative to the card's position on the screen also proved annoying, and the use of the prompt at the bottom for hiding the zoom or showing more options didn't play well. I also couldn't show the card image as big as I wanted due to needing room for the prompt, an ability, and the details at the top, plus the details would not have been able to be as big as I wanted either.
As a result, I decided to completely change how activating cards and zooming work. I've now made it so when you press on a card, it's selected with a green outline, and its options appear above it partially transparent so you can see cards behind them. You can then drag your finger up and release it over an option (or above the first option) to select that option. This makes it so playing a card from your hand, for example, is as simple as putting your finger on it and flicking your finger upward. You can also still double-tap to auto-select the first option, and you can also tap the card then the option. Whenever you finger is down over an option (or above the first option), that option will become highlighted so you can read it easier before releasing your finger. Tapping on the selected card a second time will hide the options, as will tapping anywhere not covered by the options, though note that tapping on a different card will select it and show its options.
In addition, two options will appear side-by-side faded out below the selected card: "Zoom" and "Details". Dragging your finger over or below either of these options will cause the corresponding view to display immediately (no need to lift your finger). You can keep your finger down and drag left or right to switch between Zoom and Details, and then move your finger back up to the row where the card was to hide the zoom/details view. This way you can view the zoom or details for a card and activate an option for it all with one motion of your finger.
While the Zoom or Details view is shown, the Zoom and Details options will shift to the bottom of the screen to make room for the view. If you lift you're finger while the Zoom or Details view is shown, it will remain until you tap anywhere on it. You can also tap the Zoom/Details options in this state to toggle between the two if you like.
Here are a few screenshots to give you an idea what this looks like:
I'm very interested to hear feedback on this change, since this behavior being user friendly is extremely important to the success of this app. Hopefully my description of the behavior above will make it possible to visualize how it would play without actually trying it out yourself, though they'll be plenty of time for that once I can get an Alpha version released.
Thanks.
-Dan