1)You should write a php script that can check the wallets balance from a database you have written, and run a cronjob every 5 minutes.
2)Your database should include the users ID and the Address used for depositing funds.
3)Your code should read this value and display it to your user.
4)Your game should deduct the "gamecost" from the user balance and update it.



// get user balance

            if (empty($user_balances[$user_id])) {
               $bal_info = User::getBalance($user_id,$wallet['eth']);
               $user_balances[$user_id] = $bal_info['balance'];
            }

I am available for hire you can visit www.bitify.co.za for more information. My entire platform works with user balances, and assuming by your question you should not be dealing with other users funds if you don't know the basics about crypto-currencies / programming.

Good luck with your ICO, will be following the progress.  

I cannot post images?

Pictures posted by Newbies using the [img]-tag are displayed as links, because of previous incidents with spammers and trolls. See this thread for more information Images in posts disabled for newbies. It is possible to purchase to "Copper"-rank if you want to post pictures right now, checkout this thread for more information on that: Newbies can now pay a small fee to enable images.

Why can't I change my avatar?
Only Full Members and up are allowed to wear avatars. It must be no more than 120px wide, 80px tall, and 100 KiB in size. It must be a PNG, GIF, or JPEG image. It must be safe for work.

For more information why this restriction exists, please checkout About the recent attack and Avatars re-enabled

How can I find my Bitcointalk ID/UUID?

    Go to your profile
    Click on "Summary"
    Look at the URL in the URL bar (mine would be https://bitcointalk.org/index.php?action=profile;u=101872;sa=summary)
    The bold part is my Bitcointalk ID/UUID, so "101872"


What forum account levels are there?
There are multiple account levels on this forum, here is a quick list for all of them.

Rank   Required activity   Required merit
Brand new   0   0
Newbie   1   0
Jr Member   30   0
Member   60   10
Full Member   120   100
Sr. Member   240   250
Hero Member   480   500
Legendary   775-1030   1000

You get merit points when someone sends you some for one of your posts. For more information, checkout Forum ranks/positions/badges and Merit & new rank requirements.