I got a goblin coming towards me first
I see, the idea of the game is to hide/prevent monster approching, the big sword you pulled, and use all the other weapon (the ones with a beam of light above them) to kill them.
Killing them will make weapons drop from the basket at the starting area.
All weapon works slighty differently but I will keep the spoiler short here :)
Once you reach the last wave (the dragon) you will need the big sword from the start to kill him.
The hammer from the start of the game is the only weapon that do not break, finishing the game without using it may make for an harder challenge.