The film currently holds a 50 % ` Rotten ' rating on Rotten Tomatoes , based on 120 reviews ; the site 's general consensus being that although the film `` may seem like just another Harry Potter knockoff , the film benefits from a strong supporting cast , a speedy plot , and plenty of fun with Greek mythology '' . 50 % of 130 reviews were positive according to Rotten Tomatoes ; the site 's general consensus being that although the film `` may seem like just another Harry Potter knockoff , the film benefits from a strong supporting cast , a speedy plot , and plenty of fun with Greek mythology '' .