Like Google Chrome, Microsoft Edge introduced a new minigame in November of last year that would tide you over for a couple of minutes when you're offline. The surf game was launched initially as part of an Easter egg hunt day prior to Ignite 2019 before it became available for Insiders since late February.
Following a few months of preview, Microsoft announced today that the mini-game is available as a permanent offline game for everyone on Edge, starting with build 83.0.478.37. It can be accessed by visiting edge://surf or it can be played when your device is not connected to the internet, of course. That means the error page will display a link to the game when you're offline.
The game borrows heavily from the old SkiFree on Windows where players must ride the waves while avoiding islands, fellow surfers, the kraken, and other obstacles. Items such as hearts are up for grabs in order to extend the players' lives as well as boosts for faster speeds. There are three modes you can choose via the game settings menu, including a classic surf mode, a time trial mode, and a zig-zag mode with an option to surf as many gates as you can. The game has also added support for keyboard, mouse, touch, and gamepad.