Well, you could just make acid pools wider, so the player has to spend more time crossing it.
Yeah, but I like where you're going with this. I suppose you'll keep gaining items as you go through the game. Have you considered being able to return to previous levels with new items to find new areas? (example: you get a jetpack in level 5, and there was a platform out of reach in level 3. You go back and can get some goodies there)