Yes, some projectiles can be absorbed in Spirit form when right clicking, gain 5 projectiles, regain 1 health.
And if you wonder what '1' health is, well, when you start the game you have 5 health, when you have all health eggs you have 10 health.
At least, that's what I think. ^^;
Oh, and be sure not to get TOO close to the projectiles, cause you can still get hurt by them in spirit form.