First I want to say that this game is extremely difficult, even on "Stalker" (Normal). Near the end of the game you will not be able to purchase bandages or medkits, and trust me you will need them. If you run out of medkits you will have to turtle your way through massive and very cheap spawning enemies. Now I don't think this is a bad game, if it was intended to be hard then they nailed it. The problems I have with it are such:
-Enemies have a hitbox inefficiency, some enemies take massive amounts of ammo (1-2 clips) and others take a few shots even if they are the same. Don't bother aiming for the head it works on the lesser enemies.
-The game goes from a really decent RPG to a linear shooting gallery where you hind behind numerous walls and crates with a "hold" crouch which does not fit well.
-The ending of the game is something that unless you find out ahead of time you will never beat it. Unless you see that you need ungodly amounts of medkits and bandages "YOU WILL NOT WIN".
-There are bugs yes but sometimes freaking out and hitting the move keys enough you can get out. If not you better have saved recently.
-Autosaves are only when you go to new areas, other than that if you don't save you will be playing this game a very long time.
-Gun upgrading is expensive for the lack of money you normally have. Plus the weapon will lower in condition very quickly so money in this game is your best friend.
-Finally, the money, if you don't farm and chore through the swamps and all the anomalies to find artifaces or pick up every gun you see, you will have "NO" money.
Other than these things I find that it is weirdly addicting and quite fun and funny sometimes. If you like really hard games well this game is great.