Thanks for playing!
Ah for the fake coins I guess it is not obvious enough huh... the way to identify fake coins are by looking at their spin direction. If you look at the UI to the top left you may notice that the coins next to the true coin counter and the fake coin counter spin in different directions; they correspond directly to the actual coins in the game. I thought the UI shows it well and my other test players figured it out without reading the instructions too so I thought I had conveyed the message well -- but I will keep this in mind!