I'm still struggling to beat the 3rd stage boss. The first form ain't bad, but the second part Fs me right in the A.
It doesn't help that this is more or less a 1 life only game. When you die and respawn at a checkpoint, you're too weak to be much of a threat any more.
For giggles, I checked out Violent Soldier to see how it's differs. It seems pretty close to the same, though maybe a tad easier. Outside of enemies taking more damage (which I freely admit might be in my head), the main differences I've noticed are different attack patterns for the first stage laser twin mid boss and nice lightning in the red backgrounds of stage two; neither change in the US version is for the better.