Revert hextris.io link as its broke

README.md

@@ -991,7 +991,7 @@ Multiplayer game servers and [browser games](https://en.wikipedia.org/wiki/Brows
 
 - [A Dark Room](https://github.com/doublespeakgames/adarkroom) - Minimalist text adventure game for your browser. ([Demo](https://adarkroom.doublespeakgames.com/)) `MPL-2.0` `HTML5`
 - [EmuLinkerSF](https://emulinker.org) - EmuLinkerSF is an open source Kaillera server. Kaillera is a client/server system that any emulator can implement to enable netplay over the Internet. ([Source Code](https://github.com/God-Weapon/EmuLinkerSF)) `GPL-2.0` `Java`
-- [Hextris](https://github.com/Hextris/hextris) - Fast paced HTML5 puzzle game inspired by Tetris. ([Demo](https://hextris.io)) `GPL-3.0` `HTML5`
+- [Hextris](https://github.com/Hextris/hextris) - Fast paced HTML5 puzzle game inspired by Tetris. `GPL-3.0` `HTML5`
 - [Legend of the Green Dragon](https://github.com/lotgd/core) - Legend of the Green Dragon is a text-based RPG originally developed by Eric Stevens and JT Traub as a remake of and homage to the classic BBS Door game, Legend of the Red Dragon, by Seth Able Robinson. ([Demo](http://lotgd.net/)) `AGPL-3.0` `PHP`
 - [Lila](https://lichess.org/) - The forever free, adless and open source chess server powering lichess.org, with official iOS and Android client apps. ([Source Code](https://github.com/ornicar/lila)) `AGPL-3.0` `Scala`
 - [Mindustry](https://mindustrygame.github.io/) - Factorio-like tower defense game. Build production chains to gather more resources, and build complex facilities. ([Source Code](https://github.com/Anuken/Mindustry)) `GPL-3.0` `Java`