This is a very nice expansion for Hero Kids. My kid loved the characters the second he saw them. I was worried that the characters (which are all animals) would have cutesy animal attacks. Thankfully, it seems like the attacks and powers are pretty much from a selection of existing characters, so they are all pretty cool (not from a kid's point of view, but mine!). Sure, the illustrations look pretty cute (for the most part - although the turtle would fit into a typical adult game of D&D without a problem!), but choosing these characters doesn't introduce anything that diminishes from the game. In fact, they're a welcome addition to a game that already has a TON of characters to choose from. Depending on the theme of your adventure, these characters may just fit better. Or at least give you and your kids a new flavour of character to choose from. Definitely worth the price to add some more replayability to an already very replayable game!
I was surprised to see another hero pack some out considering how many heroes there already are. Seriously, I've printed out the entire collection of character sheets and there is a thick stack. The switch to animals was actually a very smart idea, as it really doesn't seem like they're just recycling the same old thing. I'm very interested to see what other hero packs get released.