Good game, lame enemies.
1.The graphics are fine for their time.
2.The sound is very immersive, both music and sound effects.
3.There is real tension at all times, mostly from raw anticipation and paranoia. But right when you start to calm down the game throws something else at you ^^.
4.You must think on your feet. I absolutely loved the running sequence involving the rock worm.
5.Atmosphere and the "feeling" of the story. Its what penumbra is all about. That and easy puzzles :P
Bad:
1.Low lighting can give me a headache after a while.
2.Dogs. Yeah, great for the first few encounters, then they just get old. After a while of getting spotted you'll learn that you can just run right by them and they become even less interesting.
3.The combat is horrible. You rarely have to fight, but when you do the outcome is pretty random unless you have stuff to throw at your enemy to stun them. But then again it makes each fight hectic and desperate.
Overall:
Its a great game for its day. They seemed to get a little lazy with level design and with the enemies though. I recommend this game to anyone who enjoys slow, atmospheric games.