Are these games online or off line?
If they are 'offline', try disabling (if you don't need them or use them and if they are enabled) the following:
3. Data Connection
To do this go to :
Menu > Settings > Wireless and Networks > WiFi > swipe button left to off.
Menu > Settings > Wireless and Networks > Bluetooth swipe button left to off.
Menu > Settings > Wireless and Networks > more > Mobile Networks > Data Connection tap to enter, select off.
Disabling the Data Connection means effectively that you are disconnecting the internet option from your phone and also you will not be able to send or receive any MMS messages (texts with pictures). Ordinary SMS messages (texts only) however will still be able to be sent and received and your phone will still work as a phone. If you wish to use the internet or to send or receive MMS messages simply turn on the Data Connection option.
By disabling these features you are freeing up phone resources which can then be used for other uses. For example with the WiFi and Bluetooth options enabled your phone is constantly looking for networks/connections which not only uses resources but power as well. With the Data Connection enabled there may be apps on your phone which may (stress may only) be accessing the internet in the background, unbeknownst to you, not only using resources and power but also eating into your download quota.