Hey, author here! Awesome to see this on Hacker News, and that so many still care for this great computer! Happy to answer any questions/take feedback if you got something on your mind.
Does cross-developing in 6502 asm still give much advantage compared to C (via e.g. cc65)? Or have modern tools more or less closed the gap?
The question arose after I played the impressive modern atari 8-bit (48kb ram) game His Dark Majesty [1], which development the author documented on his homepage [2] & used c.