Yeah, tablets have to be run in "mouse" mode, there's been isues with this before and I've use my own tablet to play this game too.
You need to go to your tablet settings (how I have no clue, diferent for every tablet) and somewhere change from tablet to mouse mode.
The 'technical' stuff behind this is that the tablet immediately PINPOINTS the cursor, while a mouse moves the cursor, this game does not work with pinpointing, to keep it simple.