I'm making a casual game on iOS platform. But I'm not sure Do the consumers like my game. How can I make a market test for my game?
That is a very nice question! I have been thinking about the same thing lately.
I don't know how are you doing your development. But you always need beta testers. If you don't have any. I would start there. Beta testers could give you great hints about your game. What is wrong / what is right / what should be changed. Beta testers are players as we all are. They know what entertains them. They will help you make the game better. In my opinion it is far better then releasing the game as ClassicThunder mentioned.
If you released the game as a demo. You could get very bad ratings and it would ruin your game awareness. Just because you want to test if public likes it.
If you have beta testers and / or you feel very confident about your game. You might want to release a preview of your game to Youtube and then post it to Reddit and such. It will take some time, but you will see just from the comments if the game is looking good or bad for potential customers. This is again to avoid bad ratings.
Then you might want to release a demo. But I would not recommend it.
I've only done stuff with the WP7 market place but if apple allows it I would suggest releasing a free demo, posting a link to it at places such as Reddit's IndieGaming subreddit, and then seeing how the reviews go. Plus you can get direct feed back in the comments. Also no blow back in reputation if it doesn't go over well (No bad reviews sitting there forever keeping customers away).