Nice one! Yup, as a game creator and programmer, it can get quite chaotic indeed, especially if you end up with spaghetti code xD
I did encounter one probable bug and it seems like the algorithm to solve your node connections isn't recursive. On the puzzle where the output says "Answer: 75", I connected the cast to the final string add before connecting my final int result to it. The cast did not update and neither the add and it was outputting "Answer: " instead. Restarting the puzzle and connecting my nodes the exact same way, but connecting the int to the cast before connecting the cast to the add, the output was now as intended. Wondering if this is intentional or an actual bug. Nonetheless, sometimes coding does feel like that where you have something that should work but the output isn't correct. Soooooooooo task failed successfully? xD
Minus that one detail, very creative entry!