For other mobile users:

The black boxes are data; they are automatically picked up. You're swiping to move the cursor that places the data. The "write file" button writes the data.

It sort of works for me, but it feels far from pleasant/responsive. Feels like it only ever goes in one direction at a time. Dragging diagonally has your file stuck.

You need to swipe. Works on iphone 13 + chrome.

I tried swiping, got nothing.

I’m not sure what else someone would interpret as drag and drop on a touch screen. That’s gonna be swiping.

it's more just dragging than drag-and-drop; slide finger to move the blinking in one direction; no tapping

works for me with iPhone13 + Safari

It’s because the game ergonomics are questionable. You can only slide files sideways, not past other files. Your phone isn’t broken, not is the game engine. The game rules are.

I got other things I’m supposed to be doing right now so I’m gonna go do those.