Summary
You'll either love it or hate it.
The Good
The immersion. The graphics and sound combine in an incredible way to enable you to completely immerse yourself within the title - it is this factor which will determine whether you fall in love with the game or not. If you can let yourself be immersed by it you'll fall in love. If you can't, then you'll likely hate it, and not understand the attraction.
The plot, though very basic, works well enough, and the way that each level (and your character) evolve is incredibly well thought out. There are no life-bars in this game - you simply change form as you are damaged or gain energy - from the base form of a sphere, through gradually more complex humanoid models, to a floating sound-form, to the final form of what appears to be a baby, the transition has to be seen to understand just how well it works.
The Bad
Nothing! But, if I hadn't been so immersed, I would likely have picked up upon the brevity of the game (though to get the "true" ending and all bonuses you're going to have to put in a huge amount of effort, so for me it wasn't an issue), and the fact that it's "only" an on-rails shooter.
The Bottom Line
An experience, and one that I can't guaruntee you'd enjoy. Approach the game with an open mind and hopefully you'll get the most out of it.
