The Omniwrench is your starting melee weapon. You can swing it in a jumping, a one-two-three combo, or you can toss it like a boomerang. It can also be upgraded. In addition, it is useful for grabbing out of reach bolts with the boomerang.
The Walloper resembles a large punching glove. It's first available on Gaspar for 7500 bolts. One punch is three times as powerful as a strike with the Omniwrench.