In the Simon Game project explanation there are four external links for sounds.Each for a color.
I wonder about the sound for wrong. One need to derive it from one of those sounds or is there some link for that as well?
I think you can make it up for yourself. It isn’t provided. I used another sound I found online somewhere but you don’t have to make it sound off when the user gets the answer wrong. It’s all up to you. Good luck!
I’ve checking for sounds in internet and there are a lot, but one need to download the file and after one should upload it to codepen as asset, but for that one need the codepen premium.
Do you know some web giving access to external links for sounds?
You could upload the sound piece of your choice to your cloud drive (could be google drive or dropbox or others) account and get a link to your file from there. Here’s the tool and instructions for google drive - https://sites.google.com/site/gdocs2direct/