Thanks for all the feedback! I designed the sets mechanic because as you said it still technically requires getting more cards and was more fun in playtesting then just getting more cards. I was a little disappointed that the theme was lost with this decision but it was definitely more fun.
Hey, if more fun was the cost of diverting from the Jam theme a bit, then it is 100% worth it.
My rambling may (or may not) have some truth to it, but it is a lot easier to say something than to implement it, and just writing down a concept or an idea is not the same as actually fully making it and playing it. So in other words, being a developer is a lot harder and more complex than just being a critic with observations.