Locating the Zone entrance[edit]
Of the remaining zones that you must visit, two of the bosses are quite strong and can deplete your health very rapidly, so you're going to need to boost your defense. In order to do so, you need to explore a new region of the house. You've been to the attic, now you must visit the basement. There are two ways to get there, one entrance near the front of the house, and one near the back. You should start off by searching for the entrance near the back.
Room F[edit]
To start off your search for the next zone, you should enter Room F. This room can be reach a couple of ways, but the easiest way is to return to Room E, which you used to access Zone 3. You can either exit out to the hallway and walk over to the door that leads to Room F, or you can simply transfer directly from Room E to Room F through the door in the wall between them. Either way, you'll find machine gun ammo along the East wall, and a potion on the North wall. But that's not all you'll find. If you hit the North wall in the right spot, you'll expose a ladder behind the wall. This time, that ladder leads down to the basement. When you're ready "GO" down the ladder.
Room U[edit]
After taking the ladder from Room F down, you'll arrive in this gray room, which is rather empty. All that you can find in it (besides the ladder that you arrived from) is a supply of grenades along the West wall. After you've collected them, head outside to the hallway. Only one other door will be accessible to you, so enter it to reach Room V.
Room V[edit]
At first, Room V appears to offer more promise than Room U, but after opening everything there is to open, all you will find is more grenades, and a valuable potion. Be sure to collect them, and explore the door along the West wall. This leads to Hidden room d. Head inside.
Hidden room d[edit]
Naturally, as a hidden room, this room has no doorway access to the hallway outside. It seems to dead-end here just as Hidden room a did. You'll find machine gun ammo and grenades right out in the open for you to collect. But don't give up your search. There's more to the blocked off hallway to the left of Room V. If you hit the right location on the West wall, you will create an entrance to Room W.
Room W[edit]
You've found the way into the single room at the far end of the basement. Stepping out into the hallway will reveal that this is the only door that you will find. That's ok, because all that you're looking for is right inside. First, grab the potion from the West wall, and then open the lone door along the North wall to access the entrance to Zone 8.
Into Zone 8[edit]
Compared to some of the zones you have visited in the past, you may find this zone to be considerably easier. There are no special tricks, and if you take the right path, you can easily breeze by most of the enemies without even needing to stop.
In order to avoid confronting most of the enemies, it is best to occupy the middle path whenever it's available. With slimes on the floor and bats near the ceiling, the middle path is almost free of any enemies, except for the occasional winged demon that dives down. This is good since you'll want to conserve ammo for the boss fight.
Boss[edit]
At first glance, you may feel as though you have no room to maneuver when the boss attacks. The truth is, the arch in the ceiling is all the space you need to avoid attack. The boss will occupy the left end of the tunnel or the right. Every time you hit it with a bullet, it will tuck itself into a ball, and hurl itself to the opposite side. As long as you are standing under the arch, you have plenty of space to leap up and let the boss pass harmlessly beneath you. Wait until the boss stops flashing from damage, and then a split second while it remains blue before jumping up.
The boss is guarding the incredibly useful Defense Suit. It's so useful, in fact, that it's not a bad idea to interrupt your own pattern of attack to run over and grab it when the boss is on the left side of the screen. It will significantly cut down the amount of damage that you take from the boss if you mistime your jump, as well as reduce the amount of damage that you take from all the other enemies. It will even eliminate the penalty to your health when you use a grenade. Shoot the boss until it is finally defeated, and collect the eighth laser gun piece. Then make your way back to the zone entrance, assured that you will take less damage from enemy attacks if you get hit.