It's so and so. OK when it's on sale but not otherwise.
The game desperately tries to be another Portal but fails pretty much on every level to live up to it. It constantly references Portal but not in a clever way. It even reuses jokes from Portal.

Where GlaDOS is at times snarky, ironic, sarcastic, trolling and passive aggressive the guy who is constantly talking at you in this game is just being a pompous prick 24/7. That shtick gets real old real fast.

The environment doesn't make any sense in a pre-shadow context - particularly the switches.
Also you really have to NOT think about the game mechanics...because why would you not just pick up a light and point it at your feet and walk out of there? Yes, the game forces you to only turn lights in one plane but there's no reason given for this constraint.

The audiologs (which seem to be a must-have for games of this sort) don't make much sense, either. Even the recording woman says recording devices are forbidden and no one can leave the facility so no one could have smuggled any in. Where do these crates of recorders come from she's using?

The entire game would actually have been MUCH better off without any of these and any of the monolog from Virgil. It would have been spooky and cryptic instead of badly written and acted.

Some of the puzzles are fun. Some are merely tedious. The game does look good at times, though.

4 out of 10 (at reduced price).

A fun Portal-esque puzzle game with the guy that voices Agent 47. Good game.

Fun game. Feels very similar to Portal. So far the puzzles have been challenging enough to be fun, but not frustrating. I'm about half way through.