What was your process for getting the code? You claim to not be a programmer, but decompiling a unity game isn't straightforward.
I used a programm to convert certain files to a Java /Unity Script from there on you can just scroll through parts of the code. Most is asset placements as well as scene placements, mostly spagetti from what I can tell, dont know íf the dev has a certain system for coding , but doesnt seem like it to me. From there on you have to search for certain key words he uses, thats how i managed to somewhat coordinate myself in there. Just so you knwo I didnt make any changes to the code and just watched how it likely was programmend and estimated how long it would take. You can also see that most of the code for cell scene reperat with changed variables like names, locations, requirements as well as finding the locations and so on. The hard part was for me to find special events like henchwomen / heroine scenes which I still dont t understand.
Most of my IT knowledge I got from advanced IT classes during my bachelor. Its simple coding knowledge and NOT coding knowledge in unity, but I understand enough general coding, to kinda understand some of the simpler lines, as well how long it would take a professonal or somebody with experience to make them.
And even if you have limited IT knowledge you can see that there are some code lines which arent implemented and will confuse people who try to make future improvements on the game. Even making mods for the game like the money one and heroine capture mod which exists are really hard to code in this confusing mess and may break the game in a future update when they decide to change or modify the source code.
From my limited point of view I would suggest them to pause development for like 4-5 month and either fix the code (difficult and may break the game) or to rebuild it from scratch , so you can make updates more easily. In the long term, if they plan to keep updating for 2 or more years it would make their lives a whole lot easier. I think, coding may take them like 20 hours max per update and managing conflicting lines, bugs and errors are likely the main center of work to get and update out, not counting assets.