It IS a rather naive show and some things might be a bit... forced. But it certainly does have potential:
All in all, it can be a very good show. It just needs some tweaks to make it stand out.
- The art work is good: quite bright and warm, matching the comic tone. The comic book details give it a the final touch. - Needs a bit more originality on the jokes side: although I didn't find it boring, it didn't make me laugh. Should use a better script; could use the music to note irony, sarcasm, etc. - The siblings are a rather stereotyped new moneys. Something would have to be done about them to make them less predictable (eg, the sister's ways to get back at the people who made fun of her should be more original or looked more thoroughly planned. They could even become an every episode thing) - Grint's character's clumsiness and awkwardness slightly reminds me of Alan Harper, so it can work for the general public, though it seems more than obvious that a lot of growing is planned for him. Maybe making him afraid of more things or more afraid of certain things could work as a personality definer as well as a joke-trigger. However, I liked very very much the 'I'm not sure who I am' theme (guessing it isn't over with, of course).
All in all, it can be a very good show. It just needs some tweaks to make it stand out.