Galaga has a timing issue and runs pretty slow on the E125 (may be related) and the coin key seems to not work.
Try setting it to free play in the MAMEUI.
> After running the mamce on my E-125 casio I can't get it to play. I just look
> and look at the demo game of one of my favorite games---Galaga--- And I wonder
> IF I could just PAY someone TO MAKE IT F@#@ WORK!!!!!! jUST MAKE IT f#@$%# WORK.
> So PLEASE let me know if anyone knows How I can get to play. Thank you very