Far from me wanting to launch uPlay in order to run a steam game - and get performance issues for my trouble - Child of Light is a really good RPG that reminds me of Grandia and other games of that style - one with a time bar where you act after a certain point and can get knocked back and do the same to your enemies - mixed with a stylish 2d adventure where you fly around collecting items and solving puzzles. I'm not a big fan of poetry as the base for video game writing, but the actual game is pretty fun to play.
One core aspect of CoL is the little firefly ally that follows you around. It's important in many game systems; You use it to solve puzzles by shining light at things. You stun enemies to get surprise attacks on them, you can use it to open most chests and collect most items. In battle it can be used to heal your character by holding the mouse over them and slowing down the enemies by doing the same thing. You also collect HP and MP from bushes using the mouse cursor. It's pretty novel, but it's a bit clunky. Especially using it during battles, as it could be done differently - and probably better. For instance, just requiring you to click an enemy and then it would be slowed as long as you don't click anything else. Same thing for healing.
The exploration part of the game is quite alright. You start on foot, but you get the ability to fly pretty quickly and it makes exploring easier than in most games. There is plenty to see and many chests to open, enemies to fight and secret bosses to discover, so the game rewards exploring around. The treasure you'll find are many; permanent stat boosts, one-use potions and Oculi, crystals that you mix together and equip on your characters - think about the gems from Diablo. Enemies need to be attacked from behind if you want the battle to start already in your favor, and there are plenty of traps around - spiked floors, moving spikes, etc - to give the exploration a bit of challenge.
Your party is composed of many characters, all with their archetypes. Some will have faster attacks and healing, others many different elemental spells. Some can taunt and are obviously supposed to be 'tanks'. Your main character can fight with sword and magic, but she doesn't have much otherwise. It's really frustrating that you can only have one other party member. Even if you can switch pretty much at-will, choosing only one other from your roster of characters makes it so the strategic values of some skills are debatable; Taunting for instance, or buffs that affect 'the whole party'. Is it worth using such skills when the single target versions won't take much more time? Also since you need to move your Oculi around depending on which characters you plan to use, it's best just to keep your best ones on Aurora and on one or two other characters.
And it's a shame because the battle system is plenty fun; There is a good deal of customization with the skill trees and you can make each character more or less go in the direction you want them to. Mixed with Oculi on their gear and they can get pretty unique. The lack of 'analyze' functionality or a monster compedium makes the whole element weakness thing a bit tedious even if some obvious matches like fire monsters being weak to water are tossed in there. Hitting monsters when they're about to cast and making them go backwards in the action bar is a key element while juggling with the fact that they'll do it to you too if you're not careful. I really wish you could have three characters at once, it wouldn't make having a healer or support caster feel like a waste of a party member slot.
To conclude, there is much to do and see in Child of Light and the deep battle system and characters will be plenty interesting for RPG fans. The progression in skills and Oculi is satisfying and the battles can be challenging and almost puzzling at times - since enemies react differently to certain actions. The story isn't much to talk about, but it's not bogging down the game in any way, I'd recommend it wholeheartedly.