Also, that's the order of visiting rooms in level 4 which I used(I'm posting this because it's actually possible to do very bad things in level 4 and spoil the stats you got in levels 1,2,3):
×Etrance =>
1E(killed one of mad eyes here, one which guarded the poiton) =>
1N 1E(took the poiton behind the greckle door) =>
1N 2E(taken poiton from the antlion and moving south) =>
2E(kill the grayman) =>
1S 2E(first visit) =>
1S 1E(killed the mad eye, took all poitons and moved to 1S 2E through south passage) =>
1S 2E(took attack bonus before striking the grayman) =>
1S 1E(again reaching 1S 2E using south passage) =>
1S 2E(killed the grayman now, took all the keys) =>
1S 3E(killed the grayman, dropped the trapdoors, took the poiton) =>
1S 4E(took the attack bonus) =>
3E(killed everybody there) =>
then a return to 2E, moved to 3E from there =>
3E(took the green key) =>
4E(opened one of the green doors) =>
1S 4E(took the second green key, plus used the
Click here to view the secret text
×secret passage to hidden room at 2S 4E and taking all HP poitons there
and then moved to 1S 5E(two times, first time activating pressure plate there, second time taking the attack bonus) =>
return to 4E, open the second green door =>
5E(take all bonuses, DO NOT EVEN TRY TO KILL THE KING - HE'S TOO STRONG FOR NOW!) =>
return to 3E =>
1N 3E(take attack bonus which is behind the greckle door, then kill the golem) =>
1N 4E(kill the grayman, return to 1N 3E through the passage which was guarded by the grayman) =>
1N 3E(drop trapdoors, take the blue key) =>
1N 2E-2E(there's a little chamber with poitons in 2E, it might be helpful) =>
5E(now open the blue door, head to the northern room with the anti-goblin blade, take it, kill two goblins that guard the way back, reutrn to the goblin king passage) =>
NOW IT'S TIME TO KILL THE GOBLIN KING.