Thank you for the feedback!
1. The points are gained from the little pink-purple dots on the ground that drop when killing enemies, I might add a sound effect to make it clearer that you are getting them.
2. There are no purple rings that spew out larger enemies. Bombs do spawn every 30 seconds, which can be picked up to kill enemies, so you might be thinking that those are spawners. My bad, gotta make that clearer too! And yes, a definite issue with this game, and some of the bosses, is that you can just go in one direction and avoid them all. I don't want to limit the play area completely, but i'll see if I can think of something for that.