I have never loved and loathed a game so much as this one.
The presentation is beautiful. Rockstar always has an amazing approach on their games. I loved the voice acting. The graphics are beautiful.
In fact, I loved the entire idea of this game. But the more I played on, the more I couldn't wait for the game to end.
The gameplay is clumsy (as it is in most of Rockstar's games. The last stand theatrics were borderline moronic. The cover system was finicky. The soft lock aiming locked onto people behind cover rather than the one closest to me shooting at me. There isn't much freedom or variety. These are all minor annoyances.
What really ruined the experience for me was how HARD it was. I was playing on medium difficulty and I would pop my head out for merely a second and get my head blown off in from 2 or 3 bullets. You die really easily. This is 100% a trial and error game, and some people liked that, but I found it the most tedious experience I've had in gaming in a long time.
Don't get me wrong, I love a challenge, but by the time I reached the last few chapters of the game, it wasn't remotely fun anymore. I bumped the difficulty down just so I could charge through it and get it over with. And to be honest, the most fun I had playing MP3 was when I put it on EASY. Which is rare and silly, but true. I hated having to re-watch cutscenes all the time, and re-do the same part over and over.
I just finally finished the game just for the sake of the story and as much as it could have been another fantastic R* title, I'm so glad I didn't buy this at MSRP.
But this is only an opinion, and there are many worse things you could spend 20 dollars on. Give it a go.