The demo includesthe monastery level that has been showcased quite a few times at events and during livestreams, but of course playing it on your own TV and PS4 is quite different. The demo serves as a sort of tutorial, and it introduces quite a few concepts of the new game.
You can download it here, and it will take only 2.2 gigabytes of your hard disk (0.4 gigabytes less of the European version, which probably includes more localization data)
If you want to see more about Knack II, you can enjoy a cinematic commercial released yesterday, some recent screenshots, some co-op gameplay footage (from the same demo you can play today), another clip, a batch of 4K screenshots captured on a PS4 Pro, and the trailer released at E3.
Knack II will release in North America on September 5th and in Europe on September 6th, exclusively for PS4. There isn’t much longer to wait, and while the demo is pretty brief, it’ll possibly help to bridge the gap.