I've been developing a card game on and off for a number of months, but I've realised I'm making it for me.
That's not an issue as I'm not doing it for the money, but what do you look for when choosing a card game to play?
Personally I enjoy the shorter games, but I play a few longer ones. I can enjoy longer games if they're simple to learn. I don't like anything that requires me to read a huge manual before I even put a card down.
This might be a better question for the game design forum, but I would say initially don't make the game you think other people will like, make the game YOU want to play. Complete that task first, then start shopping it to people you know and play test it and rework it based on feedback. I think if you start trying to please a bunch of random people before you even have a completed design you will end compromising yourself and then you have something a lot of people might say they like and nobody actually loves because its trying to be too many things to too many people.
.. but what do you look for when choosing a card game to play?
Card game or otherwise, I don't so much go looking for " a new (card) game that does 'x' ". Rather, I suddenly discover one that does something that strikes my fancy (and most likely never thought to ask for in the first place).