I to was rather Impressed with metro as well, its combination of horror survival and fps gameplay made it fun and unique, although aspect of the game such as game graphics and npc models were a little uninspiring and reflects half life 2 too much.
level design was pretty cool its amazing how they were able to keep miles and miles of tunnels fresh, and going up to the surface and having to face the demons (there not actually demons they just call them that in the game i actually called them Wraiths)was pretty sweet and then the Howlers.
Mind u the aim cud use a tweak or two, long rang combat was ideal if anything got to close it was impossible hit the friggin things and the lacking of a melee button for all weapons made it rather difficult.
The chopping and changing between human enemies to mutant enemies keeps the gameplay fresh and fun,voice acting was all in a rusky accent which either made it funny or really cool and a brilliant fear and mystery element to the game make metro 2033 a diamond in the rough.