Very fun. Been playing since ~2014 I recommend watching on youtube before purchasing to see if you will like it. If it looks like you'll get anything out of it, you should definietly try it.
I knew about Metro for years before I bought it, and waited several years after that to finally play it. I was a little worried with how much it looked like euro-jank in the videos I had seen about it, and the extreme-linearity was almost a deal-breaker for me. Today I finally sat down and started it on survival mode. ~8 hours later I finished the game in two sessions and loved almost every second of it. I played on the lowest difficulty, normal. The game was a complete breeze on normal. It was so easy that I accidentally saved 1000 military grade bullets (the equivalent of Fallout's bottlecaps). Despite that, I would caution against playing on a higher difficulty on a first playthrough. There were a couple turret and wave-onslaught sections where I got completely overwhelmed by enemies and had to just memorize their spawns and pray in order to progress to the next checkpoint. Additionally, I ran out of gasmask filters exactly once. There is a portion late in the game where you need to activate a life support sytem in order to breathe freely and progress to the next checkpoint. I ran out of filters the moment I started the activation sequence, and I had an awesome moment where my character was sputtering and wheezing while desperately trying to activate the sytem in order to save his life. It added so much suspense to the scene that wasn't meant to be there, and become one of my favorite moments in the game. I had spent the entire game to that point unsure if I was managing my filters correctly, and all of that tension released at once. I worry that it might be common to get soft-locked on higher diffuclties by not having any filters and being unable to find more before the character dies. I'm not sure what happens if the game puts you in a respawn loop, and judging from the other reviews you are forced to manually restart the chapter from the main menu. With that said, Metro 2033 is definitely worth the asking price, and is a no-brainer on-sale.
