I like the concept, the movement is nice as well as the shooting but it's a but difficult to aim, could use more different enemies like one that chases you or one that is like a sniper on one of the pillars and you don't pick up the the green square to get the points since it's on the pillar, the cursor PLEASE HIDE OR REMOVE THE CURSOR IT'S THE MOST FRUSTRATING THING XD, the sounds effects use was fine but could use more like player walking or enemies dying or picking up the green square, also where is the music something like a rock or metal is fine since it's a shooter, as for the line renderer you could mess around with the red lines you see to change how big or small it gets by double clicking, could use more art since it's just square and sphere(not that I am one to talk XD).
good job :D