Very cool, I'll check it out.

O.k, I gave it a try.  You're game menu is too long, not that there are too many games to play, but there are just so many listed on the same page.  Maybe sort by the number of players instead of having every possible game listed? 

Seems like I could only play a one player game, is there a way to see if other people are currently waiting to play a game without selecting it to play?

didn't try all the games, will have to have a go a little later on.

Background image is mediocre, I'd consider changing it to something else.

[ edit: 
I was thinking about 'quiztime', if you want your domain to be a success, in my opinion, you're going to have to come up with better games.  They need to be enjoyable, and people need to enjoy competing with others playing those games.  I just don't see how any of them would provide that kind of repeat visitation.  Harsh, but I think a worthy opinion.  If you can get the 'formula' right, you'll be stupid rich.  ]

On 5/13/2018 at 4:10 AM, Fritz1 said:

BTW, did you hear the music and / or sound OK?

I don't think I did, but it could have been because I didn't have my volume up.

3 hours ago, Fritz1 said:

Do you think you can check out the other games also? If you find the time, that would be great!

I thought each of your games had over 4000 likes! ?  
Yes I can do that, but I'll probably only try the ones that interest me if that's cool.  I'll update you later.

K @Fritz1 I tried each of your single player games.  

Let's start from the top:
How many balls?
Psychologist have determined that the average person can identify groupings of 3 to 4.  Limited cases one to two more max.  After that estimates of quantity, such as 7, 8, 9, becomes a combination of groupings.  Again easier to determine if in powers of familiar groupings.  So 8, 12 so on.  Asking how many balls and then giving me 58, 59, 60, 61, 62, and 63 as possible choices leaves me with one option.  Manually counting all the balls.  Why do I want to count balls?  I don't and I don't think many people will be interested in counting 60 balls. 
My recommendation: Limit the size of the groupings to a dozen at most and make it more about time trial performance.

Double
I think you should just scrap this game because it's similar to your pictures game.  And I wouldn't play it against others for money.

Move 9, 16, 25
Have you played each level and completed them?  The controls seem to be counter-intuitive. 
My recommendation: I'd maybe recommend animating the movement of the balls so it seems to make a little more sense.  In 4 minutes I managed to sort them into 3 rows of red, blue and then yellow, only to realise it needed to be red, yellow and then blue.  How about each row and column should contain a red, yellow and blue?

Pictures
This one was easy.  It was very simple to find the correct image with the correct orientation and what not.  
My recommendation:  I would consider expanding on the idea to maybe include a more diverse set of pictures as opposed to all be an apple, or banana or what not.  I think this may be an enjoyable game it was hatched out more.

Proverbs
enjoyable be game to be this think way is I difficult to.
you gave me 12 words to sort into what I assumed was going to be a proverb?  I give you my thoughts in 11 scrambled words.  I don't think the average person is going to hammer out these proverbs correctly.  Unless they're very familiar with biblical proverbs, which then begs the question of why they're gambling on your site.

Puzzle
Personally, I have never enjoyed the tile re-arrangement games.  But I don't doubt there are those who enjoy them  It was well done.

Letters
Last but not least we have letters.  You ask me to sort 8 or 9 tiles into words.  What you don't tell me though is that the words you've come up with are peoples names.  I'm not sure if where you live you have access to a comic jumble that appears in news papers.  But here in Sask we have one called Jumble.  They jumble up 2 five letter words, and 2 six.  They only use words that have 1 answer.  So if you can unscramble the letters into two or more different words, such as forest, fortes, foster and softer then none of these words will appear in a word jumble.  You also won't see plural words such as apples.  If you see an S then it's not a plural word.  However, that doesn't discount pluralised words that don't end with an S such as Geese.  And they will definitely never use names, because it's too culture specific.
My recommendation: Stick to 4, 5, and 6 letter words, maybe even a 7 letter word as a final showdown or something.

In the past I've attempted a similar site to the one you've created but with a different premise.  What I learned is that there is an art to puzzle creating.  What you've come up with is in my opinion a rough draft to a bigger vision, I'd recommend you do more research into puzzle creation and what not.  I'll give you and example, although this one is a bit different.

Move one number on one side of the following equation to make it correct.
3013 = 10 

There are two acceptable solutions to this riddle.

 Both answers are brought about with a different style of thinking but are applicable.

Cheers!

I forgot to mention I had a chance to listen to the music and I thought it was well done.  It had that quiz like quality about it.