I am sorry for the delay on coming back to you. The issue related to the Pokemon game is currently being investigated.
PortalDev,
Display Port is supported on HD 4000 when using Win 8.1. you can check this information at the following link:
http://software.intel.com/en-us/articles/3rd-gen-hd-graphics-quick-reference-guide
We recommend using a direct connection. Most of the times when using video adapters, the signal can be interrupted and dual/triple display configuration may not work.