I love doing this kind of stuff - it's endlessly engrossing to me. Lately I've been trying to find previously undiscovered cheat codes in 1990s console games - there are lots that never made it into the magazines! (Findings are on 32bits.substack.com).

The availability of the Ghidra reverse engineering tool suite, has made this a very accessible hobby if you have any sort of knowledge of low level languages.