Poker deeply connects to human biology and our current state of evolution. I mean things like:
- visual recognition
- manual skills
- achieving state of deep concentration
- competitiveness and strategic thinking
- ability to produce high quality cards
- ability to connect through the internet
- processing complex information in real time
- the need for possessing more and more
Aliens from another planet would have to be very similar to us to play poker. But maybe they developed something similar to poker that we have never heard of.