Yeah I gave up on that puzzle after trying to figure out the right combination after about six hours since brute forcing it obviously doesn't work lol. It's my very first mastermind game so I have no idea what to do so I looked up some tips and undstood it less. Still, pretty good game though. ("This" game. Not the puzzle lol.) Enjoyed it for about two years. Guess I'll hold off of trying to progress Kuro's story for now. I'm just mildly annoyed. Not mad.
Numbers are always unique in the code, so it's not necessary to have same same number twice in the code, as you did with 1 and 2 in the first row, and 3 and 4 in the second row.
I usually start with 0, 1, 2, and 3. If all is red, I continue with 4, 5, 6, and 7. If a number is yellow, it means the number is correct but in a different spot. And if it's blue, you know the right number and spot.
If everything fails, and you still have a riddle key item, you can use it to skip the riddle.
Numbers don't repeat. So, you can just try 01 02 03 04 for the first one. And, if it's all red, then try 05 06 07 08. If you get blue or yellow, then the corresponding number is correct; if it's blue, it's in the correct order, if it's yellow, use the same number, change the order. As an example, following from the previous one: if you get blue, yellow, red, red on the second try, that means 05 is definitely the first number and that 06 is either the 3rd or 4th number. In this case, a good idea for a third try would be 00 09 06 10 since it'd tell you for sure which position 06 is in and which 2 of the remaining 3 numbers are part of the correct code.
So in simpler terms, I have 5 tries to guess what the code is. If I'm lucky enough to get at least two slots correct. Those two slots will remain the same so I can have an easier time guessing what the rest of 'em are. Thanks, I've finally done it! Though it's my fault that I thought pushing the red button would keep the same answer. My bad. I blamed it on RNG for no reason XD