Actually you can. Each Genesis has a special ability as a result of the operation. For Python, he can grow as tall as a Skyscraper. Murph can emit Anti-Matter. Minerva, she can digistruct her weaponry on the fly. And you, you can control your density. You can become as heavy as a Dreadnought. Or as light as a feather. Doing either changes the density of your atoms, and so, allows you to walk through walls.