A mobile browser game can feel just like a native app by supporting portrait...

https://wiki-book.win/index.php/Switching_from_WiFi_to_Cellular_Breaks_My_Browser_Game_Session:_Causes_and_Solutions

A mobile browser game can feel just like a native app by supporting portrait mode for easy one-handed play. It loads quickly thanks to smart caching, so you jump into the fun without waiting