I tried finding this game for a long time since I last played it and honestly it still holds up. I went Vet on hard and had fun chain head shotting with a deagle/getting incendiary shots off with smgs. The game is challenging with the different types of enemies (small ones that close the gap, big guys with a lot of HP, ranged attackers) and has that feeling of hopelessness when they surround you (like it should).
I did find the game to be a bit of a grind in the later sections but loved how well the healthkits/ammo were placed to keep you just barely surviving (finished the tunnels with literally no ammo)
Unfortunate that it looks like no episode 2 came out but enjoyed this one regardless!