What's particularly crucial is that Igniculus is the secondary role when Child of Light is played cooperatively, with one person controlling him and the other Aurora. It's hard to gauge just how well the asymmetric gameplay will be perceived as one player will have a bit more of a passive role.
Growth is not only a central theme to the story, it's also specifically reflected in the gameplay as well. Child of Light takes this to its most logical conclusion, being framed as an RPG. Leveling up not only represents getting stronger through turmoil, but also discovering and finding confidence in your own abilities. While everything has a storybook feel to it, Child of Light disguises some complexity.
Besides keeping an eye on your health and MP, you're primarily going to be concerned with the action bar. Similarly to other JRPG active battle systems, characters and enemies will all progress across the bar. Once you near the end of the bar, you'll be prompted to input an action, all of which have their own speed to completion. This last section of the action bar is the most important, hitting enemies or in turn being hit yourself will interrupt your action pushing you back towards the front of the bar. Thus it's possible to nearly chain lock an opponent out of acting at all.
Igniculus also has a part to play in the combat as well, either controlled by your or your co-op partner. He can blind enemies, slowing their progress across the action bar. Thus timing becomes very key to success, as just trying to wail away with your most powerful, and slowest, attacks is rarely going to work out well for you. You'll need to balance using Igniculus to slow down specific opponents, either to let you focus on a separate one or to line your attacks up to disrupt them. There will be these great moments where you're running low on juice for Igniculus and you're trying to race that enemy to see who acts first.
There is just no getting away from talking about how great this game looks. I sometimes found Aurora's model slightly jarring when compared the the other visuals and I did experience a few hang-ups on the PC version I was previewing, but the aesthetics on display really do look like something pulled straight out of a wonderfully illustrated children's book. The levels are quite large and open to exploring, there's tons of hidden chests and collectibles hidden all around the maps. And the backgrounds, which have a watercolor-esque quality to them, are quite stunning.
In a lot of ways, Child of Light feels like it's attempting to accomplish for video games what Pixar did for animation. A seemingly simple veneer reveals a much deeper and richer game, but at the same time it's able to operate and speak on a number of levels. There's something for JRPG fans here, literary junkies or even folks that simply want to see an interactive story told through a character that isn't a gravelly space marine.