Apart the first few levels the difficulty isn't consistent. I found myself stumbling over hard puzzles in the middle and having no problem with the last several.
I don't like it. The game consists of running around a basement collecting fuses and turning valves so that you can blow up a boiler (because for some reason that's sure to get you out). It's a pixel hunt for random items, most of which are just boiler-explosion-plan components. Boring and derivative, certainly not scary.
Okay, the stone fall boss fight is ridiculous, the controls are awful, and there is no "Back to map" button, so if you want to go back to level select you have to reload the game. Fix it.
The one thing that I don't like is the seemingly infinite amount of aliens - I'd like to be able to just kill them all before proceeding, instead of being afraid of every corner.
Everything would behave a LOT differently than simply getting lighter as you go is this was anything remotely close to actual physics.