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

https://yenkee-wiki.win/index.php/Why_Switching_from_WiFi_to_Cellular_Breaks_My_Browser_Game_Session%E2%80%94and_How_to_Fix_It

A mobile browser game can feel just like a native app by supporting portrait mode, so it fits your phone screen naturally. It loads quickly and remembers data through caching, cutting down wait times