@Raygrote, There are in fact ways to go up and down. Notice that you often end up swimming in water, you might even hear some of those bubbles you can use to breathe underwater. You can usually swim under the polar bears, however they can swim too and will dive down if they find you. Unfortunately, there are once again walls underwater as well so you will have to dive up eventually. I haven't really found a good way to beat that game, because the polar bears only move very slightly slower than you do. And especially if you get walled in, you have no chance. Add to that the fact that there doesn't seem to be any way to tell where you can surface and where your way up is blocked, and this game is hard almost to the point of being annoying for me. But, it can be done. I've even unlocked it, it just isn't very likely. I have no idea if the floating pieces of ice actually move or not, but staying at the surface is a pretty sure way to get yourself devoured so I usually don't bother.
The game after that where you're being pursued by a bear and needing to catch fish to maintain your energy is another really annoying one. There often don't even seem to be enough fish to catch, so that the bear will eventually catch up. You can't really move left or right very much either, because that likewise gets you killed more often than not. People suggested waiting a few moments to be able to catch passing fish, but that also tends to mean that you will become bear food. It seems you have to get lucky and find at least a few big fish right in front of you in the first watery area, or you most likely won't make it. And I have gotten 20 points on that game too, but for me at least its very, very unlikely. So I'm not sure if there's some special trick to it, because I need to get past that game again to unlock that frozen manor thing, but... Yes, these games definitely seem to be a lot harder than the ones in other worlds.
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