Short version: I played all the way through, and I'm glad I did, but I'm not sure I want to play it again.
Long version: Very much a 'see for yourself' game. The graphics are unique, the gameplay is interesting, the enemies are innovative. I love the difficulty system (die or don't die, and unlock the ability to add selective challenges [enemies get stronger/faster/vindictive etc] depending on how you feel. The story is - by design - very linear, and gameplay with mouse and keyboard becomes very demanding in places. (hear sound, dodge, fire - only often the sound for one particular enemy plays only AFTER it attacks you, and healing leaves you no time to dodge. Those levels were... not fun.) And I really resented that you unlock new weapons/skills by finding them in the game... which means you need to play the rest of the level with the new weapon instead of your super-upgraded favourite one.
This is very much not a game for newcomers to the genre.