You got to use a pink boomerang. I don't remember what it's called in-game, but...
Using a Pink Potion on a Boomerang gives you one of the best weapons in the game. It has a kind of "rope" connecting your hand to the boomerang, whenever you hit any kind of terrain, it pulls you towards that location. I think it pierces trough enemies, too.
You can use it to get these eggs on the screen shot, to get to the helmet near the end of the second stage more easily, to get a red potion somewhat in the middle of the second second-to-last stage, among others. (You can also get yourself killed by using it, so be careful)