Air Fortress/Stage 7

Entrance approach

 * 1) After a single set of wave motion enemies, you will have to fly below a pillar.  Beyond the pillar are three barriers blocking access to three energy items.  You'll have to carefully remove the bottom two in order to collect the energy.
 * 2) Immediately after are two more energy items between two platforms with barriers on either side.  Beyond that are two energy items beneath two barriers.  Destroy the barriers, collect the items, and then fly up and destroy the barrier above to gain access to energy above.
 * 3) Next comes a maze of items and barriers.  At some point, the path will diverge, so you will be unable to collect 100% of the items, but you can head down one path and collect one energy item before doubling back and taking another.
 * 4) As you exit the maze of passages, shoot the barrier above, swoop down and collect the energy items, then double back and head up to collect two bomb items.
 * 5) A set of large wave motion enemies, the only other enemies that you'll face here, will appear just before you enter the fortress.

Fortress interior

 * 1) As soon as you exit from the elevator, your goal will be to exit to the left and drop down to the elevator on the left side of the bottom, while taking as little damage as possible.
 * 2) Head down the elevator and take out as many blue robots as you can before heading right.  Eliminate the energy-wave shooting enemies on either side of the square cannons before approaching the elevator at the top.
 * 3) Take the elevator up, and float to the next elevator at the top left corner of the room, again trying to sustain as little damage from enemy projectiles as possible.
 * 4) Ride the elevator up, step out of the elevator, and start flying to the right.  Take the upper path when the room splits, and destroy the blue robots and flame orb that attack.  Patiently remove the two energy-wave enemies on the ceiling before approaching the cylinder.  Break a hole in the removable wall, time your passage through the cylinders, and break the other wall open.  Then quickly drop down to the elevator, avoiding the hopping sentry if you can.
 * 5) After you ride the elevator down, you will encounter a white butterfly.  These butterflies aren't particularly dangerous, but they have a lot more health than yellow butterflies, and they will relentlessly follow you from room to room.  They take around four bombs to defeat, and they are hard to hit.  Do your best to remove it while rotating cubes fly up from the lower section of the room.  Halfway down, you will see two flame orbs and a clone.  These enemies are very dangerous, so you should remove them as quickly as possible.  When you're past them, drop straight down to the elevator on the left, ignoring the second clone you encounter at the bottom.
 * 6) Ride the elevator down, and prepare to battle against a hopping sentry.  When you remove it, carefully take out the three energy-wave enemies on the floor and ceiling.  Take the lower path and destroy the mini-core in the way.  Try to remove the energy-wave enemy on the ceiling before proceeding to chute A in the back of the room.
 * 7) The room you will arrive in is exceedingly dangerous.  Near the top, you will encounter not one, but two clones, followed closely by a flame orb partway down.  You cannot simply drop to the bottom and hope to escape dealing with them, and you need to travel back up to a chute that is guarded by a third clone.  Bomb the enemies that trail you near the top so that the clone at the bottom isn't so difficult to deal with.  Then take chute D.
 * 8) When you arrive, you will see one blue robot, an energy-wave enemy on the floor, and a mini-core.  Take them all out before proceeding to the left.  Then take out the next blue robot while approaching the blue breakable wall.  You don't have to deal with the wall turrets if you don't want to.  Destroy the core, and then use at least one bomb to break one of the gray blocks beyond the core.   Shoot the rest of the wall out and take chute F.
 * 9) When you arrive, you will immediately be set upon by a clone.  Take it out quickly, then destroy the mini-core, the two blue robots, and the energy-wave enemy below the mini-core before proceeding back up the right side of the room, and taking chute H.
 * 10) Coming out of the chute, you will see a lot of enemies to the right, including a hopping sentry.  The sentry may be the only enemy you must deal with.  Head to the bottom passage and proceed right.  Watch out for the two energy-wave enemies on the floor and ceiling, float past the square cannons, and continue on to the mini-core.  Destroy the mini-core, and then you'll need at least one more bomb to take out the gray blocks, as well as one of the blue blocks, to access the escape Lightspeeder and be on your way to the final stage.