Once you have a backup of your game in a format like .n64 , .z64 , or .v64 , you need to get it onto your Chromebook. You can download it from cloud storage, transfer it from a USB drive, or copy it from your local hard drive.
While primarily designed for Windows, there are workarounds to get Project64 running on Chromebooks through Linux.
None. You simply visit the website and upload your game file.
Audio stuttering is common, performance depends heavily on browser efficiency, and features are limited.