This is a common problem with the web version, which is currently being worked on by Blackfur. The web version takes a lot of time and patience to work on and because of this, it does have some problems like this, which Blackfur is aware of. The itch version is suggested to use over the web version, if you can :)
this is.. partially true, but mostly false
there was a way to run the development version using an android app, but it was highly buggy, crashed very often, and, from what i've heard, no longer works at all since fullscreen mode was added. please make sure you fact-check your claims in the future to avoid spreading misinformation :)