Clarification for pg. 26 of the rules, "You can only attack creatures or conjurations that have a life value."
I presume that I can have my creature's attacks target friendly creatures? I'd like to be able to bop creatures that have been hit with Sleep incantations.
Unless your opponent does it for you its one of the few ways to get passed sleep.
The rules for targeting would be what applies to this
Target: Every spell must be cast at a target. You may
select the target only if it matches the requirements listed
on the spell you are casting. Some spells may target
objects with particular traits or subtypes.
Targeting also applies to Melee, Ranged, and Zone attacks. So as long as the targeting conditions are met you can attack the object.
As a side note you can use this to bounce around Chain Lightning. Sometimes shooting your own stuff is a good thing.