Ironically, the notification that launches when the player selects Impossible difficulty on a phone (chromium based browser) cannot be dismissed because it's below the accessible screen area, making it impossible to play.
There's enough text visible to imply the schtick, but either having a conditional vertical scroll if screen.height isn't large enough or moving the confirmation button to the top of the notification would make it playable on this platform without a download. (I haven't tested the apk, the download version might have the same issue).
Edit: It's particularly strange because the previous screens do have vertical scrolling of the press and drag variety.