The idea is that you use the recoil from the beam as a jetpack! I've seen a few people not get that so will add it to the tutorial if I work on this again.
Oh believe me, I did that and had a lot of fun with it! It can't be used reliably to traverse small distances or to move diagonally. Spamming the jump button is viable, but it's not as smooth as a weak jumppack would be. It's a very minor issue, all things considered.
One bigger issue I found was that my beam ended up so powerful that I punched through the bottom of the level, fell into the void, and couldn't get back up.