This game is pretty good, some of the puzzles really threw me for a loop and the gels were a great addition to the game i think.
That said, i do have some problems with it, mostly with the humor. I thought this went way overboard with some of the jokes, to the point where a lot of it feels very forced. The stuff in the first portal felt a bit more subtle at times, and way toned down (in frequency more than anything), and as a result better (to me). "Hahah, you walked into my trap except you just escaped except hahah there's another trap" etc. you can only hear that stuff so many times before it gets downright annoying. Also, get ready to hear
jokes everywhere for the next 5 years! (sigh). Some of the signs were hilarious though, i'll give them that.
I also wish this didn't focus so much on the characters, because i don't really think the game needs them at all. Same with the story, but then again, that wasn't the reason i liked the first game.
TL;DR - Gameplay, mechanics and music are awesome, humor, story and characters along with the focus on them, not so much