Part 2: Galactic InfernoUpdate!
The sand worm can take a little bit to figure out. It fires shots from its tail, so you should work harder to avoid lining up with the tail than to actually deal damage (unless you have level 3 laser at which point it dies almost instantly). It has another attack where it goes underground and launches exploding mines, but unless you fuck up or pick a bad weapon for this level you shouldn't have to see that attack.
The evil seed reminds me of the hand of nod from tiberian sun. Destroying the seed sprays a few of the same blood particles Tanker shot at you, so watch out, they CAN kill you.
After that it's just a matter of surviving the rain of stones. I'm not entirely sure, but I think there at least are a few different patterns they can fall in, even if it's not randomized. I found it to be best to stay in the middle and watch the top of the screen intently and dodge from there, moving back to the middle when possible so you don't get cornered.
Rubikin (Rubicon?) is as annoying as it's easy. It trails you slooowly around the screen. Don't fall for the trap of trying to get extra shots in or it will just corner you. Just keep circling it, pulling it towards each corner of the screen and then come back around to get a few shots in.
Now however, we've come to the midpoint of the game, and this is were we separate the men from the boys (I think it's safe to say that the boys are better at video games).
I give you...