Here is the full list of all 14 Gobs and Gods Demo achievements.
Just win a fight. Any fight.
Flee from a battle.
Let a gob die.
Loose all your gobs.
Play until the mid-demo event.
Unlock the demo item.
Play until the end of the demo.
Talk to another god.
Kill another god.
Learn a skill.
Teach a skill to one of your gobs.
"Convince" the guards, the goblin way.
Bride the border guards.
Show your pass to the guards