One of the most significant skips in the game is spider skip. In order to do this skip you need to pick up Jump man Suit from level 3. With Jump man suit equipped you need to go to T shaped platform right before the spider boss fight, on the platform you need to double-jump, into rage leap, into jump, into flutter (spamming attack button in order to reduce fall rate). You need to obtain the majority of your height before you pass the tree, otherwise you are going to trigger the spider fight. If you trigger the spider the fastest option available to you is to die as quickly as possible and try again because even if you get an ideal spider fight it can take multiple minutes where as restarting the level will take less than a minute.