Menu and Initial Feedback:
This feedback is mostly negative, but I'm not saying that you're bad at what you do, I'm just telling you how you can make it better in the future there is a lot of work to be done here. You should probably take it off the market to avoid lots of negative feedback that you can never recover from, and when you make the experience better, re-upload it. I have taken my time to suggest a complete re-design for you. I shouldn't have, but I did. Now to begin:
The whole friends import thing is very annoying. You gotta think of a better way than doing it like this. Perhaps, just download the info you need, and not the photos, or use facebook's API to get a random friend for the game when you need it.
The graphics can surely do with improvement. It's nice that it shows a random photo of a friend on the mode selection screen, but it would be better if this photo was not completely opaque, or at least stick a black semi-transparent label above it. Doing this will also help, because the images aren't the best resolution. It will draw the eye away from them. Also, the images are stretched. It would be better if you kept the aspect ratio of the images, and either enlarge the image to touch OR fill the edge of the screen.
Also, as far as the menu goes, It doesn't look great. Instead of Game 1, Game 2, etc. Give the games a real name, much like the Memory game is called "Memory". Also, do you really need the friend quiz logo next to each game mode? How about splitting the menu into built-in games, and 3rd party games (for memory). I don't really like the idea of 3rd party games, but others might.
Game 1 (Name to Photo):
The green box at the bottom could do with a re-design.
The text of the names should resize instead of take a new line if the name goes outside the box (to a limit of pixels, and then allow letters to go over the next line). Alternatively, you could also re-size the boxes so that smaller names have smaller boxes.
Audio feedback is nice, but when I tried this out, I had the sound off. You should provide visual and touch feedback (vibration) too! The phone should vibrate a little if the answer is wrong, and a "wrong" sign should appear or a cross go over the name.
I think this would be more fun if it kept a score of correct guesses vs incorrect guesses, instead of allowing the user to guess again until they are correct. If they get it wrong, show them the correct answer by drawing crosses over the incorrect answer and leaving the correct one there, or just hide the incorrect ones from the screen altogether to draw the focus of the user to the correct box.
Sometimes two friends will have the same first name. Keep this in mind. If two friends have the same first name, perhaps an initial for the last name would help.
Game 2: (Age order)
Take my advice from the first one.
This could play out by allowing the user to order the contacts first, and they would earn points for the correct ones, and lose for the incorrect ones. It will then show the user the correct answer in order below their answer.
The actual layout was quite nice for this one. Good job, but it may need to be re-designed a bit if you want it to play out how I think it should.
Game 3: (Guess age)
Most of my friends fall in the same age range, so I was spamming the 16-25 button a lot.
A better way this could play out was if you give some random ages and the user would select the correct one.
For example, if the friend was 20, it might give 19, 20, 21, 22, 23
If the next friend was also 20, it might give 17, 18, 19, 20, 21
this is so that the correct age isn't always in the same spot on the screen, and it would make the game more challenging
Game 4: (Guess location)
The layout for this one was very nice, but the google tiles would not download for me. I was presented with a maps widget with the fb logo in the middle, and the google logo in the corner, but no tiles.
Also, a lot of friends might live in the same city, which would make this game less challenging, or present the user with more than one correct answer.
Maybe you should remove this one. Think it out.
Game 5: (Guess hometown)
Same feedback as game 4
Game 6: (Memory)
I didn't try this one. I like how multiple photos are shown... do that for the main screen, but slower.
Game 6: (Guess birthday)
The year should be shown too. Also, in the settings, you should be able to switch between MM/DD/YY and DD/MM/YY