As far as young kids enjoying it, it might depend on the age of the kid and if they are normally active. My son always loved it even when he was very young, but he watched the movie so knew what he was looking at. We would always take our time and look at the details in each room. If they (or you) haven't seen the movie it could still be fun to see what's in the rooms and figure out how they were using everything. You might tell your kids the basic story, family shipped wrecked on an island could only use what they had on the ship.
Bad knees, I have them and don't have any problems with it. Again, I just take it slow.