oh! I dodn't know about this one. "Melvor Idle: An Idle/Incremental game based on Runescape". I spent quite some time with Runescape some long years ago.. good olde times; I wonder if it's still alive.

Edit: master Zenwaichi's post beats mine :P

Where are you playing this game, can you share the link? probably https://melvoridle.com/ ?

Edit:
> money is 4bytes*2. Actually, everything seems to be coded like this. HP, inventory items, experience, skills..
> speedhack works