I just try to play it on my phone and it works fine. So the problem might be in the obsolete Android version of my Lenovo tablet( it's on ART but is obsolete indeed...) or in his screen resolution wich is 800x1200 and not FHD. Or just because it's Lenovo...I think the problem is that we are all using Ren'py to make the Android editions, and I am not an Android developer, so I kind of have to take what it gives me unless I look for something else. I will do extra research to see if I can get to the bottom of why some Android platforms require an "ok" button, while others do not.
Good luck!