Thexder/Levels 6 - 10

Level 6

 * Level 6 is the second cavern stage. It can actually be cleared extremely quickly if you opt to take only the highest pathways.  You will bypass much of the activity in the stage and end up very close to the level's exit.  You will face some Eips before you reach the long tunnel that deposits you at the final cavern were a Bat and some Snakes are waiting to greet you.  If you're quick, you can bypass the Snakes as a jet and move on to Level 6.
 * If you are interested in the bonuses that the rest of the level contains, of which there are very few, there is a set of 8 Baffins on the bottom left corner of the map, and some Centibeets (along with a Flower) towards the right-most dead-end of the stage.
 * To reach the Baffins, you must take the first tunnel that drops down, and continue on to the second, and double back to the left. In that bottom tunnel, you will face three Bats, three Eips, and three Trobsters, all of which are very dangerous if you let too many appear and swarm around you at once.  Your reward at the end will be the energy boost provided by the Baffins.
 * To reach the Centibeets and the Flower, the safest path is to drop down the first tunnel again, but continue to the right when you reach the second tunnel drop that goes left. Beyond that are some Bats until the tunnel opens up again.  Stay to the bottom, and ignore the Baffin that is holding a number of Brix in place.  It's not worth dealing with the damage those Blox can deliver.  Continue until you encounter the Centibeets.  Kill all four, and proceed to the dead end.  Defeat the Throbster in the tiny alcove and fire in that space to reveal the Flower.  Retrace your steps to exit the level to minimize damage from enemies that you have not encountered.

Level 7

 * If you try the same trick in Level 7 that you learned in Level 6, you'll be in for a surprise as the pathway along the top dead-ends. There are some Baffins, a Centibeet, and even a Flower to discover, but there are so many Bats along the way, it will generally be more bothersome then if you left it all alone.
 * Instead, if you take the lowest paths as soon as they are available, you will find yourself doubling back to the left, where you will encounter a number of Bats. Eventually, you will enter a carved out room that contains three Baffins as well as three Yugazogy.  Make sure that you clear out the floor hugging Yugazogy before continuing on to the right through the lowest tunnel.
 * Eventually you will reach a clearing with water on the floor, and a stationary Bat up above. If you destroy the Bats, a deluge of Balders will fall from the compartment above.  This isn't necessarily so bad.  Let them fall and stay safe, either as a jet floating above, or shooting at the as a robot (but don't waste too much energy.)  When the deluge stops, fly up into the chamber to defeat two Centibeets and reveal a Flower.
 * Now you must fly through two chambers occupied by a couple of Eips. It's best to fly past them instead of stopping to fight.  You will lose a lot of energy in the time it takes to transform.  Once you get beyond the chambers, you will climb up to a welcome sight of four Centibeets.  Destroy them before continuing.
 * There are four Red Missiles to deal with. Then continue to the right and you will find a Baffin.  Hiding behind the Baffin is a Flower.  Destroy them both.  Then double back to the left.  You can see what's in store for you, four Eips lying in wait to swarm around you as you fly through their territory.  If you've already used your shield once so far in this stage, it's a good idea to activate it again.  Otherwise, it's possible to zip past all four Eips as a jet if you lure the last Eips away from its starting location before proceeding to the exit.

Level 8

 * Level 8 starts out in a very cruel fashion. Free floating Mines and a Morb are just waiting to attack you as soon as you arrive.  It is highly advised that you use your shield for this encounter and forfeit the no-shield bonus.  Once the Mines and Morb are destroyed, you must destroy the gates blocking your progress.
 * The next section will see you flying ahead of a series of walls that are attempting to crush you. This is very easy to accomplish as a jet, so transform and fly through the winding gaps until you make it all the way to the left.  The Yugazogy waiting for you on the other side can be flown over if you don't wish to shoot at it first.
 * Next you will enter an area where you can stay low, or fly high. You're going to want to explore both areas for the three flowers that can be found.  Each level is guarded by a single Smite which can take a lot of damage before dying, so shoot from as far away as possible.  Once they're clear, your laser will find two flowers in the upper level, and one in the lower level.
 * From here, it looks like you have three choices, a low, middle, or high path to take, but you really only have two. The low and middle path intertwine and dead-end together.  If you insist on taking either one, stay high along the middle path to reduce the number of Smites that you encounter.  A wall will appear halfway through a small tunnel.  Turn around and lure the wall all the way out before continuing.  Behind a lone gate, you will find three hidden Flowers.
 * Ultimately, to leave the level, you must take the high path. Doing so will put you in the path of two smaller objects that are similar to the large combination of Mines and Morb that you faced in Level 4.  Situate yourself so only one column of each object is visible on the far right side of the screen as you attack it to minimize the amount of swarming that occurs when the Mines are freed.  Between the two objects are three Baffins and a hidden Flower.
 * Once you pass the objects, it might be tempting to make your way down the winding tunnels guarded by the Brix, but it's very easy to take a lot of damage, and the Centibeets at the bottom are nothing compared to the abundance of Flowers you've already found in this stage, so let it go unless you like a challenge. Instead, lure the first Brix out and slip past it to continue to the right.
 * After one more Smite, take the lower path to discover a Baffin hiding another Flower. Destroy them both and prepare for a bigger object that you will have to dismantle.  The fortunate news here is that many of the blocks in this area can be destroyed and create a narrow beam for your laser to shoot through while limiting access to the objects that break free and want to swarm you.  If you fire conservatively, you can create a safe ledge for yourself to safely stand on and break the object up.  Once it's destroy, continue to the right to exit the stage, gathering one last Flower before you leave.  You Max Energy should be pretty close to the 500% mark by now if it's not already.