This is important because Snake Pass doesn't save the game in the middle of the level so if you are doing a run for getting 100 % completion on each level, make sure to get to the checkpoint before you attempt a difficult platforming task. (gearnuke.com)
There are also several large boss creatures that can show up in the middle of a level that will require creative solutions like throwing bombs in King Dodongo's mouth to temporarily knock him out and deal damage that can lead to a critical attack. (shacknews.com)
I had saved in the middle of a level before I purchased the DLC and was happy to find that the Expansion Pack applies changes without losing any data. (mysilenthill.com)