x86-64 Playground – An online assembly editor and GDB-like debugger

Is there a version of this for a simpler ISA like for the 6502 chip, the Gameboy chip, or straight up ARM?

For ARM (32-bit): https://alexaltea.github.io/unicorn.js/ or https://cpulator.01xz.net/

For other architectures, it feels like a missed opportunity to not have an independent WASM build of MAME's debugger, as the whole project could already be built in WASM (although I think the latest versions were broken, as that target isn't actively maintained): https://docs.mamedev.org/initialsetup/compilingmame.html#ems...

This is an assembler: https://paleotronic.com/merlinplus/

This one is quite fun: https://skilldrick.github.io/easy6502/

As info for others, the site currently has CORS errors, thus it doesn't assemble/execute.