St1+2 bosses are trivial (just remember that St2 boss is only vulnerable when he's doing his big laser thing, so before and after he shoots it is when you have opportunity to damage him, the rest is dodging). I stick with blue for them in addition to st3 boss.
St3 boss:
For that guy with the boomerangs my strat is to quick kill the left turret first, if you stay far enough left, while continuing to damage it you first boomerang it throws (right side) won't get close enough to you and then you'll destroy it. Then I go to the right side and do the same thing. Just remember whenever it throws a boomerang stay centered and low, and then move straight up, then to the right side and back down. Once you get the hang of dodging them they are trivial. Then go after its main laser. Once that is destroyed it'll start throwing the boomerangs at the same time. Do the same movement I explained, centered low, move up, move to the right and back down. In between tosses it's do a couple bursts of spread shots from each side, hard to dodge it's you've no-missed until this point, if you've died once range will be low enough to dodge them easily. At this point you can each choose to destroy the arms, or just go for the kill.
St4 Boss:
I tend to use the safe spot, but first you need to make sure you have Red homing lasers. Before getting to the safe spot (either top corner of the screen), you'll need to destroy the claws. The boss has three main attacks: lunging it's claws, a green three way, and homing orb thingies from it's tail. Once you get the rhythm of each attack you just need to play safe and defensive by hugging the walls as needed while you chip away with your shots. Once both claws are gone, get to the top corner (I go for the left) and you will notice he gets very close to you, but when he move away, you can just tap right/down far enough for your Red lasers to damage it, then move back to the corner as he approaches and keep repeating this. After killing him with red laser, you will see a pickup 1Up/100,000pts, you get one or the other depending on rotation of the icon, I recommend the 1Up.
St5 Boss
One of the more unique bosses you'll encounter, though they are all pretty amazing. Time for purple laser! The boss is basically a blockade with 2 turrets that shoot a 4-way(?) spread, while 3 panels wiggle their way towards about mid screen. The main threat here is a waterfall that will instantly kill you unless you are directly underneath any one of the panels (so don't destroy them all). Now if you do destroy a panel, which will probably happen here and there since your purple laser will need to be hitting the target (some sometimes those panels are in the way), just make sure you have planned which other panel you'll hide under, each cycle the panels get replaced by new ones, so it's okay if you blow em up. Just remember to STOP SHOOTING when the waterfall is about to come.
St6 Boss
to be continued... (If anyone get's this far I'll be impressed!)
