I want to describe a possible way to develop a game for game jam and find out which part is contrary to the rules. The theme of the game jam was revealed (let’s say a furry shooter), then I started making a game. 

I begin by thinking through the mechanics and style. I looked at other small games and decided to make a game in the PS1 style and with a top view in Unity 3D. Furthermore, I remembered that in one of the old projects 

I had already done a top view and copied the solution from there. I was also once into blender and had some environment models left over and took them to the current game jam. 

Then I do most of the code and models on the go and Google basic things such as documentation or downloading something from a package manager (for example, “AI Navigation”). 

I realized that I had no idea how to recreate the PS1 style and googled the solution. I found something I liked and added it to the project after adjusting a couple of parameters. 

After 40 hours of torment, the prototype finally works, but bad luck - there are simply no sounds and music. I'm a total crap musician, so I turned to free sound libraries and found some royalty free music. 

Another 10 hours of gluing everything together using If Else and the game is ready to be thrown into the trash for release. Which part seemed questionable in relation to the rules?

Thanks for answers, and sorry for grammar, English not my first language.