I see the vision. Let me start by saying that it controls well and is very responsive, which is great.
However, blink, and you miss the preggo content. It took me standing still and slowly shooting the gun to realize that the spawns were growing in size based on how many shots they took until they were too pregnant to move; at first, I thought they were just plopping down upon defeat into a kneeling pose. Keep cooking, and I'm sure that this will spawn (pardon the pun) into a satisfying preggo doom-like.
Pregnancy content: 2/5 (If it weren't for the game description, I wouldn't know what the preggo content was)
Gameplay: 4/5 (Controls are responsive, quick, and easy to pick up)
Creativity: 3/5 (I can appreciate the Doom style)
Jam Theme: 2/5 (the progression happens too quickly, and, again, I needed the game description to grasp the progression)
Overall: 2.75/5 (If you ask me, a few tweaks to the pacing would go far. Such as slowing down how fast the enemies become pregnant and grow. Some visual tweaks could go far too, such as shading and posing (that's not to say the art is bad, as I think it's good).)