Right now I'm struggling with stage 4 in Gaiares, I can get to what I think is right before the level boss, but its taken a bit of practice to get this far.
So this means you can get to the X-shaped zone with the snake that fires the five-way spread shot?
Not to derail the entire thread, but here are a few tips for the game in general:
1. E-smash is the most useless weapon in the game, period, I can't find any useful offensive use at all, so don't get it and if it's taken by mistake then dump it for any other weapon at the next available non-E-smash TOZable enemy.
2. Stage 2 snake midboss gives V-laser. TOZ it three times to get max V-laser. It shoots through walls. Get rid of it right before the boss battle by TOZing one of the G-beam enemies that fly in and fly out rapidly. It makes that boss battle take less than one minute.
3. On stage 3, only power up the T-missile to 2nd level firepower. It's less powerful than 3rd level but then again the second level firing rate more than compensates for that. Furthermore, the missiles emerging from both sides of the ship make the diagonal fired missiles of the 3rd level T-missle entirely unnecessary. Even the guillotines just before the 3rd level boss go down that much faster when fired upon with 2nd level T-missile.
4. Stage 4 is relatively straightforward, just don't accidentally TOZ a missile with level 2 T-missile because there's no way to power down in the game.
5. The X-shaped zone is best navigated using Low ship speed. Wait in the safe area of each firing pattern until the spread fires, then just use a small tap to dodge it. Return to the middle and repeat, going to the next safe area for the next pattern iteration until the pattern is done. When the screen starts scrolling again, switch to Max ship speed for the stage 4 boss battle.
I won't post spoilers for stage 5 or stage 6 except for on request. (Furthest I've reached is the stage 6 boss, but hope these help anyway.)