Hi eyp, welcome to Mobileread
I've read that games for the 505 run but no one has ported the controls to work with the touchscreen.
As far as I know there are no games or applications made for the PRS700, I believe the lack of a firmware image to restore from in the event of damage or something is what's holding most developers back.
If you are brave enough and have the skills please give it a try, I'm sure all of us here would appreciate it new goodies