Just a quick reminder to everyone that the Theme rating is not how well the game matches the jams theme (which is optional), but how much you like and how coheisve the games own theme that it develops within it is. Onto the feedback.
Not bad for what I assume is one of if not your very first jams. You've got a solid idea and lots of room to expand into. As others have said it'd be a good start to make them spawn faster and move faster as your score gets higher. Only thing that threw me off a little bit is that the wave animation could use a few more frames, but I understand the limited time aspect.