The game is located at https://2dengine.com/mutantarcade/
Note: it seems that you are directly in the last level (5/5) using the link above. You can find an archive with the JS files here.
This is a writeup about a retired HacktheBox machine: Delivery created by ippsec and publish on January 9 2021. This box is classified as an easy machine. The user part involve to understand a process and exploit some functionnal flow. The root part implies enumeration and cracking somes hashes binary.