A fun experience, with a foreboding story that can have a happy ending if you realize you need to score Perfects. That said, the levels feel a bit too easy and small. Never felt under pressure by anything, and it fairly quickly became too easy to kill the purple. I had to hold back to ensure I killed enough of the wandering beasties before ending the level.
Also, I may have just had too many of the right upgrades, but the boss fight kind of wasn't. It never fought back at all, just wormed around while I shot it to death. Felt a little anti-climatic, though I am happy to have saved Max.