I was considering this for my PSP, but i don't know, I was hyped for killzone liberation and that turned out to be a huge waste of my money (at least for me)

BTW I can check metacritic and IGN on my own, I want advice from people that actually bought it or at least played it

Does it get boring? how good are the controls? i can see that it has pretty good graphics, but how does it look in motion? Should I play resistance and resistance 2 to get the story?

Well, thanks everyone!

its a really good PSP game, one of the best in my opinion. The controls are done very well, and you can actually play it with your PS3 controller on the TV if you want to. The "infected mode" adds some cool depth as well if you have Resistance 2. I would say if you liked the 2 Resistance games on PS3 than this is a must buy, if you are looking for a good shooter on PSP than it is a must buy.

EDIT:  You only really need Resistance:FOM to get the backstory, since the character in Retribution is also in Fall of Man.  But pairing it up with Resistance 2 add some more stuuf to the game.

What if I liked the first resistance but throught the second one was a big pile of crap? 

cool, thanks man, do i need to know the story of the ps3 ones to grasp this one?
I just played a few hours of the ps3 ones (I don't have a PS3, but a good friend does)

 Dont bother then

It's pretty good, but I thought that KZ Liberation was a great game

 I would play the first one just so you know the main story of it.  Having the second one is just a bonus, because of the "Infected Mode"

Yeah, i know it was good, just not for me, I got bored... never even finished it

I played the Demo a few times on my friend's PSP. From what I could tell, it seemed like a good game. Definitely a game to pick up when I get a PSP.

I like it a lot. They handled the controlers very well. I never played the Resistance: FOM, but I've read the story so I wouldn't be lost for RR. There's a demo over the PSN, I think that's the better thing to do before buying it.