To know what CPU is compatible you need to check the motherboard manufacturers website, which i have happily done for you: http://www.ecs.com.tw/ECSWebSite/Support/CPU_Support_Model.aspx?detailid=719&MenuID=69&LanID=0
It seems that the installed proc is a Celeron E1200: is it right?
The ECS website says that with the bios version 07/05/22 , the motherboard can support the E4500 CPU.
If you use the Ark.intel tool , you will se the differences:
I think you can upgrade with more powerful cpu (you have tho check the voltage) but there is a enough leap between the 2 above cpu that can give good result.
I am not a gamer but I guess the most important is also the GPU!