The rules state that "reusing existing code and assets is allowed". Does this include assets made by someone else or is it only allowed to reuse assets that I created in the past?

I would really like to use some free 3D models because I am really bad at making 3D things.

That's alright of course. Kenny's assets for example right? Go for it man.

Just make sure you have the right to be using them.

Kenney's assets are exactly what I had in mind. Thank you for your answer!