Thanks for your positive review.
Regarding the laser sound effect, unfortunately the C64 does not have a waveform that can imitate the arcade sound. The only way to get close would be to use two audio voices, one with the triangle or sawtooth waveform and the other with the noise waveform. Unfortunately the C64 only has three audio voices and using two for the laser sound would not allow me to have all the other sound effects of the game.