Another informative write-up by Haze along with the comparison of the two different Android pcbs. If the roms from the other pcb get supported later, it will be interesting to see the game differences on some Youtube clip.
One reason I can see the game not attracting as many customers to play the game had it been in arcades then is the difficulty of the boss stage (the spinning shape image). It looks to be way too much of a challenge (assuming difficulty dip switch setting is on easy) and would be a turn off to some customers that can take their coins/tokens and go play another game that might be easier and where their coins/credits last longer than 2 or 3 minutes.