I played through this back in the day and remembered it being alright, better than its reputation.

But returning to it today, it's a mess. Even on the tutorial level, I frequently had no clue where to go. The guns all feel awful and arbitrarily useless. You can one shot kill people with headshots, yet using the same weapon anywhere else on their body takes about 8 shots to kill them. Reloading takes an age and a day (with no auto-reload). The weapon swap interface is a mess, leading to continually losing the weapons I wanted for random ones on the floor.

I spent three hours with the single player and they all feel wasted, frankly.

Infection mode on multiplayer still rocks though.