I should start off by stating, anything you see in the screenshots or videos of games still not released are not final. They are a "work-in-progress." Even right after the game is released, some authors do "blind update" where something is changed without being announced. I try to fix a problem before too many of a particular gets sold. I am experimenting with posting videos and screen shots about a month before the game is released so others can review it and provide feed back to see if anything can be improved. Thank you for your feedback, it has been useful. After a few weeks I do have to cut off improving the game so it can be prepared for release.
I am experimenting with some different color schemes and other little things to clean up the display. Most of it is just changing color registers or changing pixels used for the sprites. Anything that requires a major rewrite of the code is not going to happen now. The sound effect system is inside the VBI that simply sends values to sound registers in a sequence. Good for gunshots, lasers, explosions, bumps, beeps, etc. Based on something I found in Computer Magazine, article called "sound command" that was meant to run from Basic. This however was not really geared towards music. Helicommander is using the 1.0 version of this routine. I have done some later experiments so it can play short music tunes, sort of a "Mini RMT." Has a small note table for pure tones. Currently it won't fit into the current version of Helicommander without some major optimizations and more compression. I pushed Helicommander to the limit, trying to add as many enemies and little extra features as I can.
I was never a big music person like KJMANN, but I know how to do sound effects. The issue I always had with RMT is that it is memory hog to do all those different instruments and different sounds. It is better for games that use up the 64K ram area, or big cartridges. Not really good for what I am trying to fit into 16K.
From what I understand, the 16K boards Video61 cost less to put a game on them versions ones the require 32K or more. Bigger EEPROM chips, Logic chips, time to burn or flash them, etc.