The game itself is good, but its unoptimized state makes the gameplay unenjoyable:
- During its entire lifetime, outside of MacOS, the game has never been updated to 64-bit. This makes it lag, stutter, and crash often on newer computers and require a lot of additional tweaking from the player's end to resolve said issues. However, in my case, using performance-improving mods (from NRass) breaks the game even further without showing any sign of performance improvement.
- The loading and saving times get ridiculously longer for every savegame over time and the performance standard has become so low that many players think 15 minutes to load a save is fast and 30 minutes (even without any custom content) is acceptable.
- Launcher still runs in the background after starting the game, using more hardware resources than needed.
- Despite the discontinuation of update long ago, the base game and all of its DLC's are still incredibly expensive.

Not worth buying at all.

Aside from the updated weapons and slightly better graphics, everything else is worse than the original game. Most noticeable problem is that the protagonist can get stuck in obstacles very easily, probably due to poor level design - you may spend 30 minutes trying to get through a level and suddenly you walk into an inescapable spot, try all you want but the character won't be able to get out unless you restart the entire level, wasting a good amount of time.
This broken remaster is not worth even the discounted price, unless you just want to collect it.

- Charming old-school styled graphics and fascinating level designs.
- Impressive soundtracks.
- Quake-inspired, easy-to-adapt combat system with a humble amount of- yet- very unique weapons.
- Multiple types of enemies with different abilities and attributes.

Worth even the original price.

Would you look at this, it's a review for Steam on Steam.

1. Really good graphics for a 2013 game, comparable with many games released years later.
   
2. Runs at considerable framerate in storymode.
   
3. Has many minor yet realistic details and secret gags.
   
4. Price does get lowered over time.
   
5. Very fun to play with friends.
   
6. Has tons of game modes and mini games that can hook you up for hundreds of hours.
   
7. Has a high diversity of firearms and vehicles.
   
8. Is a must-have for fans of high-graphics games.
   
9. Is a one-of-a-kind game.

1. Now requires Rockstar Games Launcher installed to play.
   
2. Performance optimization is not good enough in Online.
   
3. Has hidden questionable anti-grinding mechanics.
   
4. Not newbie-friendly.
   
5. PvP mechanics in Online are awfully bad and broken.
   
6. Has a lot of errors that stay unfixed.
   
7. Extremely poor anti-cheat system (if there ever is one).
   
8. There are tons of cheating services on the Internet as if cheating were legal.
   
9. Cheaters can break and even crash other players' game at the push of a button.
   
10. No shortcuts for many important in-game features.
    
11. Has low-effort weapons and vehicles balancing.
    
12. Has way too many game-breaking bugs and exploits.
    
13. Bad game logic.
    
14. Rockstar will patch any game exploit that will reduce their revenue very fast but the ones affecting players adversely.
    
15. Many players in the community are extremely toxic, thanks to Rockstar themselves rewarding such behaviors.
    
16. Has bad NPC's behaviors.
    
17. Some physics mechanics are worse than in GTA IV.
    
18. Some nice features in older GTA games are not present in GTA V/Online.
    
19. Melee combat is horrible.