I have a lenovo flex 2 15 with i7 core and 8 gigs of ram. Windows 8.1 64-bit?

Yeah. Buy a desktop computer. This is a flash computer meaning it's cute, stylish, and cheap. It doesn't have the processing, graphics, or I/O capabilities to run a decent game. My advice, use this for documents, email, basic Web browsing, and non evasive software. If you expect any better performance you are going to have a bad time.

You have i7-4510U with HD 4400 graphics
Intel integrated graphics is not very strong for modern games.
With 8GB RAM, you have basically maximized the amout the graphics can use.
Although some people have success in small but notable improvement by Iobit Game Booster, there's nothing you can do other than that and lowering game settings to a minimum, and some games still will not play smoothly.
http://www.notebookcheck.net/...849.0.html
Rank 286 is low on the list.
When you want special features in laptop design, very often that takes away from the graphics and CPU available at the same price.
The laptop is designed for movies much more than gaming.
The Y series is the gaming one. Some Z series have a graphics card at lower performance. The Flex series all have HD 4400.