I have been playing super star soldier for off and on last week. Last level boss rush is nasty. I'm having a list of issues with the game.
First if you die and have the continue where you left off power up. (Yellow Ship) its practically worthless because of how little damage your standard ship does you wont be powerful enough to defend against whatever just killed you.
-The Flamethrower (Yellow) power up can hide enemy bullets inside so if you blast a wave of enemies coming in and one gets a shot of at the edge of your shot, you can't see it and will get hit.
-The Flamethrower power up leaves the front of your ship exposed every other second
-While dodging enemies the power ups can get in your way (they come down in a waving pattern), so while maneuvering around to not get hit you may be forced into picking up the flamethrower power up.
-If you are already powered up with and a power up drop ship comes by if you don't shoot it to release power up, it will kamikaze at you across the screen and can kill you.
-Shooting the drop ship creates another problem as when it releases the power up it comes down in a wave formation. This is a big pain because unlike en enemy you can't shoot to clear it, you have to dodge it if you don't want it.
-Some power ups randomly appear (unless its point based, kill count based) so clearing certain parts seem dependent on if you can get that random ship to come for the extra power up.
-The first red power up does nothing? (Standard ship fire two straight lasers, 1 red power up nothing, 2 red power ups shots shoot front and back in a Y formation, 3 red, shots spread out all around the ship.
-The order of power ups can screw you over. If a wave of enemies come in, in addition to a wave of 3 drop ships. And I shoot the drop ships to avoid them going kamikaze on me. And a Red, Blue, Red Power ups wave down in that order. If I collect the first red nothing happens because thats how that one seems to work, then blue and get level 1 blue, try to avoid the next red but still touch it, it changes me to lvl1 useless red.
It seems that in order to clear the final stage you need the level 3 Green Power up, Blue is possible to a lesser degree. Forget Red because its useless if you get it. Yellow exposes the front and blinds your shots.
Then survive the first 3 minutes of enemies attacks while getting lucky enough that a random green appears to get lvl 3 then not get screwed over by power ups after that. Proceed to Clear a 3 boss rush, not dodge the 11 power ups that come down after the first rush cause none are green. Then defeat the last two bosses with allowing room for maybe 1 hit against you.
TL:DR SSS is a fairly difficult shooter and in the later levels becomes extremely and awkwardly difficult because of a flawed and punishing power up system.