Nice little idea! It's a bit hard to see the blue enemies on a purple floor (or was it the other way around?), but I love the shader! STOP modifier is definitely too punishing, can easily ruin your run in one go. I wonder if the shield was actually supposed to block the laser? It sounds like a cool interaction, but just a bit unusual. Also I really didn't understand some of the phases - was their a healing one? The music is nice, loved the laser drop!