There is something about this album. I don't know exactly what that something is, but whenever I listen to this album my opinions change.
When I first heard
Fear of the Dark, I loved songs like Chains of Misery and From Here to Eternity. I didn't really understand The Fugitive or Childhood's End or Judas Be My Guide. That has changed. To echo a little bit of what
@Mosh said but spin it slightly more positively, this is Iron Maiden's riskiest album. There is certainly no theme and no sonic consistency, but the musical experimentation happening here is greater than on any single other Maiden record. This also makes FOTD their most desperate record. The band (Steve) is literally throwing everything at the wall and hoping something sticks, and some if it does!
You've got classic Maiden rockers that sound like the 90s (Judas, Be Quick), you've got proggier, darker stuff (AFTSS, FOTD, Fugitive, Childhood), you've got bluesy, gritty and grimy rock 'n' roll tracks (FETE, Chains, Warrior), you've got a power ballad (Wasting Love), and you've got some straight up misfires (Apparition, FITK). I personally think the desperate experimentation here is exciting, because we ended up with some songs (that I classify as a 9 or 10/10) that classic (or reunion) Maiden would never record, such as Childhood's End, Wasting Love, and The Fugitive. There are some crazy bass and guitar (and, occasionally, drum) fills that resemble Dream Theater (or some othersuch prog metal band). I am firmly in the camp that thinks songs like Childhood's End, Wasting Love, and The Fugitive are vastly underrated.
And yet, I'm voting for:
Breeg
Be Quick
Eternity
Fear Is The Key (holy fucking Dio this song is a mess, that vocal bridge is absolutely worse than anything Blaze ever did)
Fugitive (I love it, but it's not top tier)
Chains
Apparition (a musical abortion)
Weekend Warrior (musical abortion redux)