Only lacking are minor applications of polish to mechanics and depth of content. Language rules aren't as consistent as they should be, given the clever ambiguity of some words with multiple forms such as "relieved" (adjective or past-tense transitive verb) and "fit" (noun, adjective or verb) — at least a couple multifarious words don't qualify for a given level's rule, reducing the choice to a toss-up over which one to fly over. As for the latter concern, young students should be satisfied (and tested), but the trivia buff will miss increasingly difficult or esoteric subjects like, say, famous explorers, automobile models, or American presidents in the 19th century. In the works over at Blendo headquarters? Chung and crew are certainly not for want of vigor.