So the game was really hard to begin with, until I realised... The hex numbers are two digits, and you can treat them both separately, so use the first 4 bits

So the game was really hard to begin with, until I realised... The hex numbers are two digits, and you can treat them both separately, so use the first 4 bits for the first hex digit and the second 4 bits for the second. If you were brute forcing, this reduces the search space from 256 options to 32. A good reminder of how you can handle hex. Really nice.