I like the concept of building melodies and songs from components while the gameplay systems are pointing in a different direction. And the overall high concept style currently works.
To answer your questions:
- Is this even fun? What elements are engaging and can be expanded on? What elements are annoying and need to go? -> During my play session I reached brick walls 3 times, with a full hand and absolutely nowhere to place the cards. This effectively killed my run all 3 times, leaving me with no option but to quit (at least it seemed that way, I may have missed something). This felt pretty bad, especially after the satisfaction of building up the planet defences.
- Is the time pressure right? Too stressful? Not enough? -> Didn't feel it at all, as my playthrough ended due to hand limitations instead of time pressure.
- Do the card placement rules feel clear? -> Not really. My understanding was that I could place anything anywhere to start with. But after making a decision that planet would need only that type (O/M etc) and that slot on other planets would need to be the same suit. This made sense to me, but I ran into limitations when I couldn't discard anything or had to stack meaning my hand would just fill up no matter what.
- Is hearing your final composition satisfying? -> It was nice, but didn't fully pop yet.
- UI/UX clarity -> Quite clear, but the card formatting of the casettes really threw me off initially. I think cards have a lot of baggage when I/people see them. So when I saw a "M" of hearts it became a bit confusing. Thinking "this card doesn't exist..." I'd say it could be worth changing the aesthetics of the casettes to be typed differently (i.e. colour coded instead of suited). It also felt bad to have to draw my own cards manually, as it was a bit tedious.
- Bug reports -> No bugs but my run was soft locked each time by a full inventory and seemingly no way to clear duplicate or deadweight cards. The main menu also felt a little strange as clicking "new game" didn't start a new game--it was the button next to it. haha.
Cool concept and nice spacey aesthetics.
Please give my game a go if you get the chance :)