While not as bad as later installments in this series (such as The Mark of Athena), and fairly inoffensive in a comparative sense, it certainly wasn't as good as any of the five original Percy Jackson books. 
 I think where the Percy Jackson novels were more on par with The Chronicles of Narnia or The Chronicles of Prydain Boxed Set THIS book is more easily likened to the stakes and scope of a watchable yet somewhat cliched children's television special. 
 It's enjoyable, certainly, but it has an unmistakable "junk food" feel to it. It's very fluffy, like eating cotton candy. 
 You really won't get much out of it, but it will keep you busy till the pages run out. 
 The cover is very pretty, though, so that's something.