Fun game, for a while. The fact that it only features a survival mode makes it of poor durability. Good use of glows, fades and color cycles though: it was a bliss to look at. The controls were simple, but functionnal, and the score could have been betterly implemented.
I think you need a story mode. Or at least levels. If you made ten levels (you could even put a boss at the end! Maybe some kind of huge serpenta or something), with a bit of an introduction on what those creatures are (serpenta are beings of light that prey upon their own kin, or something like that), that would make the game lenghtier. Different serpentum arenas or maps would add to that yet again, and adding devices (such as a shield, gun upgrades, speed upgrades, etc.) would surely make the game more interesting to play.
You have an excellent concept, but it needs a bit more than just a survival mode that looks good.
Nice work nonetheless.