^^
No matter how experienced in trading you are, it's almost impossible to predict what the price would be or whether it will go up or down in the next 15 or 30 seconds. First because the difference between the starting price and the ending price is almost negligible and second because 15 or even 30 seconds isn't enough to analyze the market.
As you said, it's a luck based game so just enjoy it.
I don't really think it mainly base on luck there's still need of some analysis in order to get a higher chance of winning though luck may have a role here but it's not the basic.
Though entirely it kind be seen as a fun prediction of bitcoin price