Go to Otaru for a day. Many craft shops, the canal, glassblowing demonstrations, sushi street, aquarium, etc.
Sapporo itself doesn't lend itself to much. Aside from what you mentioned (and who knows what the "etc." includes), I'd say stroll through Tanuki Koji or wander underground from Sapporo Station all the way to Pole Town and Aurora Town. There really aren't hidden gems of note.