Done this via Note 5 and TV for app use or to put Netflix on a Smartcast enabled TV.
Never tried Mame or an android game, but I cannot see why you couldn't do it, latency shouldn't be an issue.
I'll try it on my note and a Vizio 24" I have here and update later today, not sure about PSP or Dreamcast games though.
Edit:
Nope. Works fine on the phone, but it lags out on the screen. Perfect for Netflix, but I haven't tried GamePass for android
