Should I buy Penumbra.....?

[Kessos]

Yes, played it after aswell and tbh i liked it even more than amnesia in one way.
Gotta admit Amnesia is scarier in a way, way scarier but penumbra really got me into it. I had to continue playing no matter how scary it became just to find out the answers to all Philips questions. That could be both frustrating and annoying because the game was very scary. But as criticism it is great. So yes, buy penumbra!

Short Answer/TL;DR: YES BUY IT!