It reminds me the classic Snake game as enemies spawn faster and faster when you eat these... squares and it gets harder to manage this tail of blue guys.
This game lacks dynamism as everything feels laaame... Tweaking spawn rate, movement and reload speed can help it. Also, different enemies with distinct movement patterns could spice the things up.
Regarding randomness, the use of such could be better, as I continuously bump into enemies that spawn right in front of me, without any chance to survive this collision.