No, I don't suppose that.
I runned it on both Chrome and Firefox during development and now after I uploaded it here on Itch. The result is the same on both browsers, however, I noticed that the better my internet connection is the better the game's performance gets. As for you other question, I 'm not using any resources outside the projet's files.
Itch.io does mention (on "Uploading HTML5 games") something about large HTML5 run better when they are disributed as downloadable instead, but the problem is I'm not that experienced when it comes to converting many files into an actual application. I also wonder if there are technologies out there that are beginner friendly and can help me do just that.
Here is my current project structure: