if you're just going for 30 seconds, which is a fun concept, make those 30 seconds so good I wanna watch it over and over. that doesn't mean throw in as many shots as possible. quality over quantity.
there were so many shots of mediocre stuff that none of it stuck. try taking out your least favorites and working on some filler shots and transitions so you actually have time to comprehend what's going on. choose your best/favorite shots and use some location/context to back them up.