Truly fantastic work here, team.
What an atmosphere you've managed to create. It was generally anxiety inducing when the alien creatures got near to the player. The music was great.
I was a touch confused on what each colour actually does. Initially I thought you had to use each colour to defeat each type of alien, but it seemed I could kill any creature with any colour, so I'm not sure exactly what switching between colours was doing for me.
Would have loved to have seen the aliens legs animating to make them even creepier, and have had some sound effects when the aliens die, and/or some particle effects when they die.
I really enjoyed the "twitchy" interface, but I did find it a bit too much. I think dialing that back to about 50% would have been less uncomfortable to look at but still achieved the same effect.