I really enjoyed the first game, but it had some issues with difficulty: the regular levels were a bit too easy, while the extra All-Intensive Purpose was brutally hard, with ridiculous split-second timing required that made it simply frustrating (in the end, I stopped at 77% and that was already too much).
This sequel fixes things with a proper progression: the levels required to finish the game aren't especially hard, although still a bit harder than the original, and the extra levels offer a decent challenge while still not being as frustrating as AIP. Out of 70+ levels, only the very last 2 made me open Youtube for a helping hand. You can also choose to tackle the extra levels before finishing the story.
It takes a little while to get used to the goat's floatier controls, and the duo has some new tricks up their sleeve (aside from the returning Magic Hat, there are two new power-ups): but other than that, the game is pretty much more of the same, with very improved graphics and a more vibrant soundtrack. It's also a bit longer than the original's story mode, although the relatively low difficulty means it shouldn't take more than 2 hours to get through the story, and perhaps 5 hours including the harder levels.
Overall, a great way to spend some time during a weekend. If you actually liked AIP in the first game, you might be a little disappointed in the lower difficulty. But I find it a good thing myself.