It's very basic. You swing a sword at enemies to kill them. Could definitely have used some obstacles or some other gameplay elements to make it interesting. The mouse controls feel a bit over-sensitive too , and the replay level button is kinda broken as you can't move after the level restarts unless you go back to the main menu first.
The glowing sword and swing effect look pretty cool though, and i don't want to be too harsh on the game as it's still amazing you managed to make any game in 48 hours. Hope you keep at it, and keep improving. My early games were certainly worse than this.