Why just use the mouse for radio buttons? Below are 2 examples of simple and intuitive click and drag games:

First up a questionnaire for a sportswear brand; we needed to find out how often our subjects played particular sports, which could have been dull, so we asked them to drag and drop icons for each sport into their "virtual kit bag":

Drag and drop games can be a great way of getting people to think about issues like share of pocket. Here's an example of a game that involves dropping virtual money into pots to signify how people give to charity: