I'm a grown up, who has played I think 10 of the 12, and now 13 games that I think are out there on consoles and handhelds. I love most of the games as well, and even got some enjoyments of the titles I would consider to be sub-par to the rest of the series. And I didn't think it was a bad movie, in the sense of anything being upsetting or cringe-worthy, but it is definitely a forgettable movie. It's not that it's painful to sit through, there's just not a lot of caring about what's happening on screen.

All the necessary plot points are hit, the voice acting was well done, and it looks good. But there are 3 things I would have liked to have seen in this movie, that were only barely present:

1. The humour of the series. I remember finding the series overall to be pretty funny with some actual laugh-out-loud moments. The movie had a few good jokes that had me smiling (half of which weren't actual jokes, but just call outs to fun Playstation products), but most of them fell pretty flat. For a medium that would rely more heavily on a solid script, it didn't deliver the laughs I think it should have.
2. The gun-play. For a game series built primarily on crazy weapons, there's very little exposure to them in the movie. There's a short "training" scene where Ratchet basically tries out some of the staples, but that's most of his action with them. A few isolated instances where things like the Tornado Gun is fired once are sprinkled here and there, but the action is toned down significantly in this respect. Most of the action scenes seem done with standard space-age laser guns that would be found in most any animated movie talking place on alien worlds, and they don't give that frantic feeling that they should.
3. Oh, and those alien worlds. I think in the games it may take second seat to the gun-play, but almost it is able to over take it is the platforming adventure! So where's that sense of adventure in the movie? You rarely get exposure to the different worlds in this movie, as most of them are getting blown up, and the idea of exploring grand environments felt almost completely lost.

So what's left is a mediocre at best movie about an underdog that's saves the galaxy with his new best friend. A forgettable, uninspired, but bearable by-the-numbers kids animated sci-fi action movie that I don't think captures what made the source content so much fun. It did inspire my youngest to want to play the games now, so I guess that's the best outcome one could have hoped for.