Do we have to stick to the theme or is it more of a suggestion?
We're not going to disqualify anyone but it is one of the items people can score on during the voting stage so you may end up loosing some points.
The idea behind a theme is to prevent people from submitting games they have been working on for weeks (plus that it's part of what makes a jam fun), but if you make something during the jam weekend and just can't think of a way to integrate the theme, by all means submit it.