Offerings are the items that fuel your magic, continuing the ever present idea of power at a price. Your character can equip six offerings at a time, and each one supports a number of castings of a specific spell. Through the combination of spells and other character customizations, the player is able to dial into some pretty specific styles. Maybe you want to be a long range caster or a brawler who summons magical weapons to pummel foes. Spell breakdown is pretty straightforward; the more advantageous the attack, generally the lower the damage, but also the more times it can be cast before the offering breaks. For example, firing off a trio of homing spinning blades might not do tons of damage, but it can be fired off repeatedly before needing to find a source to recharge. Conversely, summoning a golem can only be done a few times, but it does a massive amount of damage to any enemy unfortunate enough to come near it. There is also a heavy emphasis on combining and fusing your offerings together to either increase their power, improve casting times or make entirely new offerings. This in turn gives you some incentive to replay missions to gather more materials, as it will allow you to power up your favorite spells or experiment with new combinations.
There is another class of spells that you can draw on, however; the Black Rites. Black Rites are powerful forbidden spells and magic that can only be used under certain circumstances, and they also demand a permanent cost. Sacrificing your skin will unleash an inferno, but your defenses will be lowered by 50%. There is however a method for reverting them. The talking journal will occasionally give you Lacrima, which is a bit like magical white out, letting you reset elements of anything written in the book. You can use it to undo Black Rite's costs or to recover broken offerings. At first this might seem to run counter to the rest of the game's emphasis on "what would you pay for power," but it's still a limited resource. This means you're semi free to use up all your options instead of restarting or grinding every time it gets too hard.
The only major issues with the whole game were due to the limitations of the Vita itself. A complex game demands some complex controls, and it can be awkward trying to accurately use both shoulder buttons, four face buttons, two control stick and the d-pad depending on how little or large your hands are. Even the basic structure of the levels themselves and entering missions leaves a little to be desired because of the Vita. The storybook narrative works well enough in the confines, but the game itself is ultimately a repetition of the same few arena sized maps and a few retextured enemies. The semi-permanent loss of the Black Rites costs could have been a more compelling gameplay element in an open world where you couldn't simply undo it as soon as that mission ended. One element that the structure does allow is that you're free to fight Magusar as soon as you feel you're up for it. Having the end boss just be an ever present option in an interesting spin on a grindy RPG.
Bottom Line: While the game is a little limited by the platform, the underlying mechanics will capture a certain style of player.
Recommendation: If you like complex action RPGs in the vein of Demons Souls and Monster Hunter then Soul Sacrifice is worth a look.