What kind of aesthetic do I want?

I really like the pencil sketch aesthetic of Emily Hughes illustrations so I tried my own digital sketch:

Original scanned in drawing

Playing around with saturation and vibrancy setting:

or greyscale?

Double page spreads:

decorative pages to go after front cover and before back cover

Could this be mistaken for butterflies instead of eyes?

Times New Roman to keep it simple and readable. Combination of written and typed up text to differentiate monster's voice from narrator's voice/main text:

Same background pattern throughout book to link pages together - also to make it less boring. Still not sure whether to keep pages in colour or greyscale. Both look good to me - greyscale one creates a darker, eerie sort of atmosphere but when I ask other people, they prefer the coloured version to the greyscale one.