Almost forgot to mention, Galaxeroids is implemented as a Progressive Web Application (PWA) using the manifold.js PWA Builder. 

This means it can be played when offline and can be installed to your PWA ready browser rocking device.  

Just select the "Add to home screen" option from your browser menu and a shortcut to the app will be added.  When launched from the shortcut it will default to landscape and go full screen.  This is by far the best way to experience Galaxeroids on a mobile device.

Unfortunately itch.io embeds the game in an iframe so you can't get the full PWA experience from the game page but you can check it out here.  Enjoy!