Too scared to play Amnesia

[Googolplex]

The Grunt looks much scarier, it's not laughable like the other monster you showed. This is laughable because it is a monster in form of a typical computer game enemie. Not really seriously.

A Grunt is not a classical monster, it's a human, a servant of Alexander who drunk some... to become a deformation.

Perhaps it's like a monster.

That's not because of the interpretation, it also looks similar to a human and not like a typical standard monster we can see in Doom or DS for example. It's something really scary because it looks seriously.

A real monster isn't scary because it is too much unrealistic.

That's why I also think the dogs in Penumbra are scarier than the other monster you showed.
Because dogs are real. Of course, a Grunt is not real, but it looks like it could be real.