Definitely dig the concept, constructing chords from a solitaire-like spread of cards is an awesome idea! Something I would really appreciate would be the ability to click a card to hear the note without actually playing it, just a way to have my ears help pick out viable combinations as I have a tough time interpreting piano keys. I second another commenter who pointed out the educational potential, this could be a great learning tool. The no-frills presentation is perfectly understandable given the deliberate constraints you were working within, but it would be awesome to see this idea dressed up with all sorts of polish :)
Thank you! :) the play the card's note idea is great, I'll note it down for the next version with the resounding feedback of in-game music theory 101.
Yeah... I'm not great at polish, but all I needed was an excuse to step it up a notch I guess. And here I thought I'd spend my next few weekends reading, haha.