Period 7-1[edit]
Period 7-1 is a looping period that is notable for it's high number of wall sections that must be bombed in order to create pathways through the period. All of the bombable walls are marked by a blue circle on the map. This is why it is advantageous to enter the period with a large collection of bombs. You'll have an opportunity to double them later in the level.
There is a treasure room in this level behind (1), but you must be careful when approaching it. If you scroll the screen over too far to the right, you will be unable to return back to the bottom of the screen where you need to be in order to locate the Chalice and escape the loop of the stage. In the treasure room, you can find a Megaton Bomb and a Super Bomb tile. After you return to the stage, be sure to return to the bottom row in order to access the Chalice, which you will find just above the first body of water.
After you collect the Chalice, return to the bottom row and continue right until you see a set of stones which block the passage up the middle of the stage. If you bomb all the way through them, and then bomb one more stone to the right of the body of water, you can quickly enter the water and then up to (2) without the need for a Waterproof item. Standing in this section of water will kill all of the enemies and double most of your inventory items.
Proceed all the way to the right to reach the end of the stage. There is a row of blocks in a small passage that is closed off by stones. You must bomb the stones to gain access to the entrance, bomb your way down to the row, and then clear the row of blocks before bombing the two stones at the end. The last stone on the left side is hiding the Key. Collect it and bomb the top of the right wall to escape.
Period 7-2[edit]
Once again, you've reached one of those mostly empty periods, where you can freely walk down an open hallway, save for the enemies which appear continuously to attack you, and the occasional staircase down to an underground tunnel. It won't be difficult to spot the entrance to the treasure room at (1), above the second staircase. In the treasure room, you will find 12 statues, 4 of which are invalid. If you hit the right statues, you can make it out of there with 8 valuable items, but no Megaton Bomb.
As usual, the last section of this stage is covered from top to bottom in blocks. However, you will only encounter one screen's worth of blocks instead of two. Get yourself firmly in the middle of the screen so that it stops scrolling, and detonate a Megaton Bomb to clear the area out and collect all of the items that were hidden underneath, including the Key that opens the exit from this period, which is found in the bottom of the center area.
Period 7-3[edit]
This stage is a boss fight against a two headed dragon named Lion. He floats above the floor of a room whose entire upper half is covered in water. Although it may seem strategic to utilize a Waterproof item in this room, it actually isn't necessary as long as you remember to stay out of the water. As the Lion hovers above the floor, it spits large fireballs at you.
Provided you have plenty of Hyper Missiles at this time, this is the best weapon to utilize against Lion. It actually takes very few Missiles to defeat him, and he tends to make an easy target. However, be prepare for him to fly off the top of the screen after getting hit once or twice. When he does this, he will continue to breath fire at you while he is off-screen, but he will dive back down and return. Once he reappears on the screen, don't hesitate to continue your assault.
It should only take around four Missiles to defeat him. Once he goes down, all of the water will drain from the room, revealing the Key to the exit underneath. Collect it and head for the goal.
Period 7-4[edit]
Although not nearly as short as Period 4-3, as you can see, this period is considerably short; only three screens long. With only one entrance to an underground tunnel hidden on the left, you'll have to make due with most of what you came here with. Additionally, the underground tunnel has a weird effect on this level. The floor is pitch black, so even when you have a Candle lit, it's not always apparent that it's working unless the walls on either side, or a tile on the floor come into view. If you travel to the top or bottom, and still can't see the walls, your candle has gone out and you need to light a new one.
There are two apparent "dead-ends" which you should be used to overcoming by now. The first dead-end can be broken by bombing the single block contained in the wall of the solid structure in the middle of the stage. The second dead-end is formed by the zig-zag arrangement of blocks that nearly form a wall from the top of the bottom of the stage. The very bottom block, and every other block above it, can be bombed out to open the passage to the final section beyond.
The Key is hidden beneath a barrel along the top of the stage once the goal comes into view. Collect it to open the goal and head through to encounter another boss.
Period 7-5[edit]
This boss is known as Fire Brain. Like the Aqua Brain, the Fire Brain is a damaged control computer that hovers somewhat randomly about the room. It launches little fireballs at you that explode and turn into fire bats that track down your ZED.
Your strategy should be the same as it was for the Aqua Brain, laying down a series of bombs that should catch the brain in their explosions. Alternatively, you can use Hyper Missiles if you have enough for a more direct and effective attack method. Continue to shoot down the fire bats if your score is low, but if your score is very high, and you have a high level of defense, you shouldn't need to worry about them very often. Either way, keep your eye on your energy meter, and be prepared to use an Extra energy item at any moments notice if necessary. Above all, stay away from the brain, as contact with it can be quite harmful, even at a high level.