Compilers for the 6502 are tricky, because of its limitations and idiosyncracies. There was a well-received port of a language called Micro-SPL to the 6502 for the Atari 8-bit computers called Action!. The original incarnation of Micro-SPL, on the Xerox Alto, compiled to Alto microcode.
Don’t tell this guy about the thing that Ritchie made in 1972.