The ZX Spectrum Analyser is a powerful tool that allows ZX Spectrum games to be analysed, disassembled, and annotated, to discover how they work.
https://colourclash.co.uk/spectrum-analyser/
It's a seriously cool tool with lots of ideas to borrow from, I also see many ideas I had over the years have already been implemented, so I take that as validation, and it helps me identify what works and what doesn't without even having to write any code.
Docs (PDF)
https://colourclash.co.uk/SpectrumAnalyserInstructions.pdf
Alpha download:
https://colourclash.co.uk/SpectrumAnalyser.zip
Video guide:
https://www.youtube.com/watch?v=QY6pZehr8uc
