It depends on the implemention. But I too hardly see a chance to do advanced roping on such a device. But for Intermediate games it should suffice.
Generally, I imagine large button-outlines over the game which fade away when the own round is over. But Worms uses quite some keys, so some functions might to be excluded to the options tab, like cycling background graphics.
EDIT: ideas for some controls which dont need extra buttons like described above:
swipe right or left edge: weapon menu
swipe top edge: chat
pull+hold worm to left: walking left
pull+hold worm to right: walking right
pull+hold worm up: aim up
pull+hold worm down: aim down
Also, note that what the mobile market is interested in is not the same as what mobile users are interested in.
I hate that microtransactions but nobody forces the developer to include that.
WormKit support is surely a big problem here too. I could come up with ideas here now, but none of them are simple enough to consider.
Generally, I imagine large button-outlines over the game which fade away when the own round is over. But Worms uses quite some keys, so some functions might to be excluded to the options tab, like cycling background graphics.
EDIT: ideas for some controls which dont need extra buttons like described above:
swipe right or left edge: weapon menu
swipe top edge: chat
pull+hold worm to left: walking left
pull+hold worm to right: walking right
pull+hold worm up: aim up
pull+hold worm down: aim down
Also, note that what the mobile market is interested in is not the same as what mobile users are interested in.

WormKit support is surely a big problem here too. I could come up with ideas here now, but none of them are simple enough to consider.